diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3304cea8fe..3bf922394b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,7 @@ Legends:
 
 ### Fixed
 
+- Fixed screen reader primary-action activation to move focus into interactive transcript activities, in PR [#5867](https://github.com/microsoft/BotFramework-WebChat/pull/5867), by [@ahonamatata](https://github.com/ahonamatata)
 - Fixed an error when a failed activity is present when Web Chat mounts, resolving [#5812](https://github.com/microsoft/BotFramework-WebChat/issues/5812), in PR [#5848](https://github.com/microsoft/BotFramework-WebChat/pull/5848), by [@OEvgeny](https://github.com/OEvgeny)
 
 ## [4.19.1] - 2026-06-09
diff --git a/__tests__/html2/part-grouping/primaryAction.html b/__tests__/html2/part-grouping/primaryAction.html
new file mode 100644
index 0000000000..b039ffa8a7
--- /dev/null
+++ b/__tests__/html2/part-grouping/primaryAction.html
@@ -0,0 +1,97 @@
+<!doctype html>
+<html lang="en-US">
+  <head>
+    <title>Part grouping: screen reader primary action</title>
+    <link href="/assets/index.css" rel="stylesheet" type="text/css" />
+    <script crossorigin="anonymous" src="/test-harness.js"></script>
+    <script crossorigin="anonymous" src="/test-page-object.js"></script>
+    <script defer crossorigin="anonymous" src="/__dist__/webchat-es5.js"></script>
+  </head>
+  <body>
+    <main id="webchat"></main>
+    <script>
+      run(async function () {
+        const { directLine, store } = testHelpers.createDirectLineEmulator();
+
+        WebChat.renderWebChat({ directLine, store }, document.getElementById('webchat'));
+
+        await pageConditions.uiConnected();
+
+        const createActivity = (id, position) => ({
+          entities: [
+            {
+              '@context': 'https://schema.org',
+              '@id': '',
+              '@type': 'Message',
+              abstract: `Activity ${position}`,
+              author: { name: 'Research' },
+              isPartOf: { '@id': '_:g-00001', '@type': 'HowTo' },
+              keywords: ['AIGeneratedContent', 'AnalysisMessage'],
+              position,
+              type: 'https://schema.org/Message'
+            }
+          ],
+          id,
+          type: 'message'
+        });
+
+        directLine.emulateIncomingActivity(createActivity('group-activity-1', 1));
+        directLine.emulateIncomingActivity(createActivity('group-activity-2', 2));
+
+        await pageConditions.numActivitiesShown(2);
+        await pageObjects.focusTranscript();
+        await host.sendKeys('ARROW_UP', 'ARROW_UP');
+
+        const activeDescendant = () =>
+          document.getElementById(pageElements.transcript().getAttribute('aria-activedescendant'));
+        const groupButton = () => document.querySelector('.collapsible-grouping__header .activity-button');
+
+        // WHEN: Narrator invokes the grouped activity's primary action.
+        activeDescendant().click();
+
+        // THEN: Focus should move to the group's first interactive control.
+        await pageConditions.became(
+          'focus is on the group expand or collapse button after screen reader primary action',
+          () => document.activeElement === groupButton(),
+          1000
+        );
+
+        // WHEN: Escape is pressed from inside the group.
+        await host.sendKeys('ESCAPE');
+
+        // THEN: Focus should return to the transcript with the group active.
+        await pageConditions.became(
+          'focus returned to the transcript with the group active',
+          () =>
+            document.activeElement === pageElements.transcript() &&
+            !!activeDescendant() &&
+            !pageElements.focusedActivity(),
+          1000
+        );
+
+        // WHEN: Plain Enter is pressed.
+        await host.sendKeys('ENTER');
+
+        // THEN: Plain Enter should continue to move focus to the group button.
+        await pageConditions.became(
+          'focus is on the group expand or collapse button after plain Enter',
+          () => document.activeElement === groupButton(),
+          1000
+        );
+
+        // WHEN: Escape is pressed again.
+        await host.sendKeys('ESCAPE');
+
+        // THEN: Focus should return to the transcript with the group active.
+        await pageConditions.became(
+          'focus returned to the transcript after plain Enter on a group',
+          () =>
+            document.activeElement === pageElements.transcript() &&
+            !!activeDescendant() &&
+            !pageElements.focusedActivity(),
+          1000
+        );
+      });
+    </script>
+  </body>
+</html>
diff --git a/__tests__/html2/transcript/navigation/focusAttachment.screenReaderPrimaryAction.html b/__tests__/html2/transcript/navigation/focusAttachment.screenReaderPrimaryAction.html
new file mode 100644
index 0000000000..a11cd7542d
--- /dev/null
+++ b/__tests__/html2/transcript/navigation/focusAttachment.screenReaderPrimaryAction.html
@@ -0,0 +1,90 @@
+<!doctype html>
+<html lang="en-US">
+  <head>
+    <link href="/assets/index.css" rel="stylesheet" type="text/css" />
+    <script crossorigin="anonymous" src="/test-harness.js"></script>
+    <script crossorigin="anonymous" src="/test-page-object.js"></script>
+    <script crossorigin="anonymous" src="/__dist__/webchat-es5.js"></script>
+  </head>
+  <body>
+    <main id="webchat"></main>
+    <script>
+      run(async function () {
+        WebChat.renderWebChat(
+          {
+            directLine: testHelpers.createDirectLineWithTranscript(
+              testHelpers.transcriptNavigation.generateTranscript()
+            ),
+            store: testHelpers.createStore()
+          },
+          document.getElementById('webchat')
+        );
+
+        await pageConditions.uiConnected();
+        await pageConditions.numActivitiesShown(32);
+        await pageConditions.scrollToBottomCompleted();
+
+        await pageObjects.focusSendBoxTextBox();
+        await host.sendShiftTab(3);
+        await host.sendKeys('ARROW_UP', 'ARROW_UP');
+        await pageConditions.scrollStabilized();
+        await pageConditions.focusedActivityInView();
+
+        const firstCardInput = () => document.querySelector('.ac-input, .ac-textInput');
+        const activeDescendant = () =>
+          document.getElementById(pageElements.transcript().getAttribute('aria-activedescendant'));
+
+        // WHEN: Narrator invokes the active descendant's primary action.
+        activeDescendant().click();
+
+        // THEN: Focus should move to the first interactive control.
+        await pageConditions.became(
+          'focus is on the first text box in the input card after screen reader primary action',
+          () => document.activeElement === firstCardInput(),
+          1000
+        );
+
+        // WHEN: Escape is pressed from inside the activity.
+        await host.sendKeys('ESCAPE');
+
+        // THEN: Focus should return to the transcript with the same activity active.
+        await pageConditions.became(
+          'focus returned to the transcript after screen reader primary action',
+          () => document.activeElement === pageElements.transcript() && !!activeDescendant(),
+          1000
+        );
+
+        // WHEN: NVDA invokes the primary action from content inside the active descendant.
+        activeDescendant().firstElementChild.click();
+
+        // THEN: Focus should move to the first interactive control.
+        await pageConditions.became(
+          'focus is on the first text box in the input card after NVDA primary action',
+          () => document.activeElement === firstCardInput(),
+          1000
+        );
+
+        // WHEN: Escape is pressed, followed by plain Enter.
+        await host.sendKeys('ESCAPE');
+        await host.sendKeys('ENTER');
+
+        // THEN: Plain Enter should continue to move focus to the first interactive control.
+        await pageConditions.became(
+          'focus is on the first text box in the input card after plain Enter',
+          () => document.activeElement === firstCardInput(),
+          1000
+        );
+
+        // WHEN: Escape is pressed again.
+        await host.sendKeys('ESCAPE');
+
+        // THEN: Focus should return to the transcript.
+        await pageConditions.became(
+          'focus returned to the transcript after plain Enter',
+          () => document.activeElement === pageElements.transcript() && !!activeDescendant(),
+          1000
+        );
+      });
+    </script>
+  </body>
+</html>
diff --git a/packages/component/src/Middleware/ActivityGrouping/ui/PartGrouping/private/PartGroupingActivity.tsx b/packages/component/src/Middleware/ActivityGrouping/ui/PartGrouping/private/PartGroupingActivity.tsx
index 4b221a11c4..cae5539991 100644
--- a/packages/component/src/Middleware/ActivityGrouping/ui/PartGrouping/private/PartGroupingActivity.tsx
+++ b/packages/component/src/Middleware/ActivityGrouping/ui/PartGrouping/private/PartGroupingActivity.tsx
@@ -2,7 +2,7 @@ import { reactNode, validateProps } from '@msinternal/botframework-webchat-react
 import { useStyles } from '@msinternal/botframework-webchat-styles/react';
 import { hooks } from 'botframework-webchat-api';
 import { getOrgSchemaMessage, type WebChatActivity } from 'botframework-webchat-core';
-import React, { Fragment, memo, useCallback, useMemo, useState, type MouseEventHandler } from 'react';
+import React, { Fragment, memo, useCallback, useMemo, useRef, useState, type MouseEventHandler } from 'react';
 import cx from 'classnames';
 import { array, custom, is, minLength, object, optional, pipe, readonly, string, type InferOutput } from 'valibot';
 
@@ -67,6 +67,7 @@ const FocusablePartGroupingActivity = memo(function FocusablePartGroupingActivit
   const { activity, children, className, groupKey } = validateProps(partGroupingFocusableActivityPropsSchema, props);
 
   const [activeDescendantId] = useActiveDescendantId();
+  const focusTrapTargetRef = useRef<HTMLDivElement>();
 
   const getGroupDescendantIdByActivityKey = useGetGroupDescendantIdByActivityKey();
   const focusByGroupKey = useFocusByGroupKey();
@@ -85,6 +86,9 @@ const FocusablePartGroupingActivity = memo(function FocusablePartGroupingActivit
   // When receive Escape key from descendant, focus back to the group.
   const handleLeaveFocusTrap = useCallback(() => focusSelf(), [focusSelf]);
 
+  // Screen readers dispatch a click to the active descendant when users invoke its primary action.
+  const handleScreenReaderPrimaryAction = useCallback(() => focusTrapTargetRef.current?.focus(), [focusTrapTargetRef]);
+
   // When the user press UP/DOWN arrow keys, we put a visual focus indicator around the focused group.
   // We should do the same for mouse, when the user click on the activity, we should also put a visual focus indicator around the activity.
   // We are doing it in event capture phase to prevent descendants from stopping event propagation to us.
@@ -115,11 +119,17 @@ const FocusablePartGroupingActivity = memo(function FocusablePartGroupingActivit
         onFocus={handleDescendantFocus}
         onLeave={handleLeaveFocusTrap}
         targetClassName="webchat__basic-transcript__group-focus-target"
+        targetRef={focusTrapTargetRef}
       >
         {children}
       </FocusTrap>
       <TranscriptFocusContentOverlay>
-        {!android && <TranscriptFocusContentActiveDescendant id={groupingActivityDescendantId} />}
+        {!android && (
+          <TranscriptFocusContentActiveDescendant
+            id={groupingActivityDescendantId}
+            onClick={handleScreenReaderPrimaryAction}
+          />
+        )}
         <TranscriptFocusIndicator type="content" />
       </TranscriptFocusContentOverlay>
     </TranscriptFocusContent>
diff --git a/packages/component/src/Transcript/ActivityRow.tsx b/packages/component/src/Transcript/ActivityRow.tsx
index 697f6d3e5f..04ebb5585c 100644
--- a/packages/component/src/Transcript/ActivityRow.tsx
+++ b/packages/component/src/Transcript/ActivityRow.tsx
@@ -32,6 +32,7 @@ const ActivityRow = forwardRef<HTMLElement, ActivityRowProps>(({ activity, child
   const [readActivityKeys] = useActivityKeysByRead();
   const activityRef = useRefFrom(activity);
   const bodyRef = useRef<HTMLDivElement>();
+  const focusTrapTargetRef = useRef<HTMLDivElement>();
   const focusByActivityKey = useFocusByActivityKey();
   const getKeyByActivity = useGetKeyByActivity();
   // TODO: [P2] #2858 We should use core/definitions/speakingActivity for this predicate instead
@@ -59,6 +60,9 @@ const ActivityRow = forwardRef<HTMLElement, ActivityRowProps>(({ activity, child
   // When receive Escape key from descendant, focus back to the activity.
   const handleLeaveFocusTrap = useCallback(() => focusSelf(), [focusSelf]);
 
+  // Screen readers dispatch a click to the active descendant when users invoke its primary action.
+  const handleScreenReaderPrimaryAction = useCallback(() => focusTrapTargetRef.current?.focus(), [focusTrapTargetRef]);
+
   // When the user press UP/DOWN arrow keys, we put a visual focus indicator around the focused activity.
   // We should do the same for mouse, when the user click on the activity, we should also put a visual focus indicator around the activity.
   // We are doing it in event capture phase to prevent descendants from stopping event propagation to us.
@@ -146,6 +150,7 @@ const ActivityRow = forwardRef<HTMLElement, ActivityRowProps>(({ activity, child
         onFocus={handleDescendantFocus}
         onLeave={handleLeaveFocusTrap}
         targetClassName="webchat__basic-transcript__activity-focus-target"
+        targetRef={focusTrapTargetRef}
       >
         {focusTrapChildren}
       </FocusTrap>
@@ -160,6 +165,7 @@ const ActivityRow = forwardRef<HTMLElement, ActivityRowProps>(({ activity, child
             className="webchat__basic-transcript__activity-active-descendant"
             // "id" is required for "aria-labelledby"
             id={descendantId}
+            onClick={handleScreenReaderPrimaryAction}
             role="article"
           >
             <ScreenReaderText aria-hidden={true} id={descendantLabelId} text={accessibleName} />
diff --git a/packages/component/src/Transcript/FocusTrap.tsx b/packages/component/src/Transcript/FocusTrap.tsx
index 73b7ac7688..1d29e81ef7 100644
--- a/packages/component/src/Transcript/FocusTrap.tsx
+++ b/packages/component/src/Transcript/FocusTrap.tsx
@@ -5,6 +5,7 @@ import React, {
   type FocusEvent,
   type KeyboardEventHandler,
   type ReactNode,
+  type Ref,
   useCallback,
   useRef
 } from 'react';
@@ -16,12 +17,14 @@ const FocusTrap = ({
   children,
   onFocus,
   onLeave,
-  targetClassName
+  targetClassName,
+  targetRef
 }: Readonly<{
   children: ReactNode;
   onFocus: () => void;
   onLeave: () => void;
   targetClassName?: string | undefined;
+  targetRef?: Ref<HTMLDivElement> | undefined;
 }>) => {
   const bodyRef = useRef<HTMLDivElement>();
   const lastFocused = useRef<HTMLElement>();
@@ -122,7 +125,7 @@ const FocusTrap = ({
       >
         {children}
       </div>
-      <div aria-hidden="true" className={targetClassName} onFocus={handleTrapFocus} tabIndex={-1} />
+      <div aria-hidden="true" className={targetClassName} onFocus={handleTrapFocus} ref={targetRef} tabIndex={-1} />
     </Fragment>
   );
 };