diff --git a/CHANGELOG.md b/CHANGELOG.md
index 85d8132ce2..01c6033d64 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -60,6 +60,10 @@ Legends:
       - [`webpack@5.107.2`](https://npmjs.com/package/webpack/v/5.107.2)
       - [`yaml@2.9.0`](https://npmjs.com/package/yaml/v/2.9.0)
 
+### Fixed
+
+- Fixed the "Retry" button to resend the message after it fails to send, instead of showing "Render error", by [@compulim](https://github.com/compulim) in PR [#5838](https://github.com/microsoft/BotFramework-WebChat/pull/5838)
+
 ## [4.19.0] - 2026-05-25
 
 Breaking changes in this release:
diff --git a/__tests__/html2/activityStatus/sendFailedRetry.html b/__tests__/html2/activityStatus/sendFailedRetry.html
new file mode 100644
index 0000000000..13120fcd80
--- /dev/null
+++ b/__tests__/html2/activityStatus/sendFailedRetry.html
@@ -0,0 +1,135 @@
+<!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>
+      function activityStatusInnerTextContained(expectedInnerTextPattern, index = 0) {
+        return pageConditions.became(
+          `Activity status should contains "${expectedInnerTextPattern}"`,
+          () => pageElements.activityStatuses()[index].innerText.includes(expectedInnerTextPattern),
+          1000
+        );
+      }
+
+      function activityChannelDataStateBecame(expectedState, index = 0) {
+        if (typeof expectedState === 'undefined') {
+          return pageConditions.became(
+            `Activity "channelData.state" should be undefined`,
+            () => !('state' in pageObjects.getActivities()[index].channelData),
+            1000
+          );
+        }
+
+        return pageConditions.became(
+          `Activity "channelData.state" should be "${expectedState}"`,
+          () => pageObjects.getActivities()[index].channelData?.state === expectedState,
+          1000
+        );
+      }
+
+      function activityChannelDataWebChatSendStatusBecame(expectedSendStatus, index = 0) {
+        return pageConditions.became(
+          `Activity "channelData['webchat:send-status']" should be "${expectedSendStatus}"`,
+          () => pageObjects.getActivities()[index].channelData?.['webchat:send-status'] === expectedSendStatus,
+          1000
+        );
+      }
+
+      run(
+        async function () {
+          const clock = lolex.createClock();
+
+          const { directLine, store } = testHelpers.createDirectLineEmulator({ ponyfill: clock });
+
+          WebChat.renderWebChat(
+            {
+              directLine,
+              ponyfill: clock,
+              store,
+              styleOptions: { spinnerAnimationBackgroundImage: 'url(/assets/staticspinner.png)' }
+            },
+            document.getElementById('webchat')
+          );
+
+          await pageConditions.webChatRendered();
+
+          clock.tick(400);
+
+          // SETUP: Send a message and resolve the call to `postActivity()`.
+          await pageConditions.uiConnected();
+
+          const sendMessage = await directLine.actPostActivity(
+            () => pageObjects.sendMessageViaSendBox('Hello, World!', { waitForSend: false }),
+            { id: 'a00001' }
+          );
+
+          // THEN: `channelData.state` should be "sending".
+          await activityChannelDataStateBecame('sending');
+
+          // THEN: `channelData['webchat:send-status']` should be "sending".
+          await activityChannelDataWebChatSendStatusBecame('sending');
+
+          // THEN: The message should have status of "Sending".
+          await activityStatusInnerTextContained('Sending');
+
+          // THEN: It should match snapshot.
+          await host.snapshot('local');
+
+          // WHEN: After 20 seconds.
+          clock.tick(20000);
+
+          // THEN: `channelData.state` should be "send failed".
+          await activityChannelDataStateBecame('send failed');
+
+          // THEN: `channelData['webchat:send-status']` should be "sending".
+          await activityChannelDataWebChatSendStatusBecame('sending');
+
+          // THEN: The message should have status of "Send failed. Retry."
+          //       This is because the message passed 20s as defined in `styleOptions.sendTimeout`.
+          await activityStatusInnerTextContained('Send failed. Retry.');
+
+          // THEN: It should match snapshot.
+          await host.snapshot('local');
+
+          // WHEN: The retry button is clicked.
+          const sendMessageRetry = await directLine.actPostActivity(() =>
+            host.click(pageElements.activityStatuses()[0].querySelector('button'))
+          );
+
+          // THEN: It should show 2 outgoing messages.
+          await pageConditions.numActivitiesShown(2);
+
+          // THEN: It should match snapshot.
+          await host.snapshot('local');
+
+          // WHEN: The first outgoing message is sent.
+          await sendMessage.resolveAll();
+
+          // THEN: The activity status of the first message should be "Just now."
+          await activityStatusInnerTextContained('Just now', 0);
+          await activityStatusInnerTextContained('Sending', 1);
+
+          // THEN: It should match snapshot.
+          await host.snapshot('local');
+
+          // WHEN: The second outgoing message is sent.
+          await sendMessageRetry.resolveAll();
+
+          // THEN: The activity status of the second message should be "Just now."
+          await activityStatusInnerTextContained('Just now', 0);
+          await activityStatusInnerTextContained('Just now', 1);
+
+          // THEN: It should match snapshot.
+          await host.snapshot('local');
+        },
+        { ignoreErrors: true }
+      );
+    </script>
+  </body>
+</html>
diff --git a/__tests__/html2/activityStatus/sendFailedRetry.html.snap-1.png b/__tests__/html2/activityStatus/sendFailedRetry.html.snap-1.png
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index 0000000000..258d62e6f3
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diff --git a/__tests__/html2/activityStatus/sendFailedRetry.html.snap-2.png b/__tests__/html2/activityStatus/sendFailedRetry.html.snap-2.png
new file mode 100644
index 0000000000..70034bae8c
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diff --git a/__tests__/html2/activityStatus/sendFailedRetry.html.snap-3.png b/__tests__/html2/activityStatus/sendFailedRetry.html.snap-3.png
new file mode 100644
index 0000000000..14ccdc02ed
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diff --git a/__tests__/html2/activityStatus/sendFailedRetry.html.snap-4.png b/__tests__/html2/activityStatus/sendFailedRetry.html.snap-4.png
new file mode 100644
index 0000000000..766bd20dd2
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diff --git a/__tests__/html2/activityStatus/sendFailedRetry.html.snap-5.png b/__tests__/html2/activityStatus/sendFailedRetry.html.snap-5.png
new file mode 100644
index 0000000000..2d4ebf29a0
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diff --git a/packages/core/src/sagas/postActivitySaga.ts b/packages/core/src/sagas/postActivitySaga.ts
index 6b021ceef6..12b166d58a 100644
--- a/packages/core/src/sagas/postActivitySaga.ts
+++ b/packages/core/src/sagas/postActivitySaga.ts
@@ -58,7 +58,7 @@ function* postActivity(
     channelData: {
       // `channelData.state` is being deprecated in favor of `channelData['webchat:send-status']`.
       // Please refer to #4362 for details. Remove on or after 2024-07-31.
-      ...deleteKey(activity.channelData, 'state'),
+      ...deleteKey(activity.channelData, 'state', 'webchat:internal:local-id', 'webchat:internal:position'),
       clientActivityID
     },
     channelId: 'webchat',
