Channel tab deeplink subEntityId not passed when clicked from within the target channel (desktop & web; works on mobile)

[lingfeidiewu]

Summary

When a deep link targeting a channel tab includes subEntityId in the context parameter, the tab receives context.page.subPageId correctly only if the link is clicked from a different chat/channel. If the same deep link is clicked from within the target channel's own conversation, subPageId is undefined on both desktop and web clients. Mobile (iOS/Android) works correctly in all cases.

Environment

• @microsoft/teams-js: 2.53.0
• Teams clients tested: Desktop (new Teams), Web (teams.microsoft.com)
• Mobile: iOS Teams app
• Tab type: Channel (configurable) tab
• Manifest version: 1.17+

Deep link format

https://teams.microsoft.com/l/entity/<appId>/<entityId>?webUrl=<url>&label=<label>&context=<encoded-context>&groupId=<groupId>&tenantId=<tenantId>

Where context is:

{
  "subEntityId": "some-value",
  "canvasUrl": "https://example.com/teams/page?param=value",
  "channelId": "19:xxxxx@thread.tacv2"
}

Reproduction steps

1. Pin a configurable tab to channel A.
2. In the tab code, read subPageId on load:

   const ctx = await app.getContext();
   console.log('subPageId:', ctx.page.subPageId);
   

3. Post the deep link (with subEntityId in context) as a message in channel A's conversation.
4. Also post the same deep link in a different chat (e.g., a 1:1 chat or another channel).
5. Click the link from the different chat → ✅ subPageId is populated.
6. Click the link from channel A's own conversation → ❌ subPageId is undefined.
7. Click the link from channel A's conversation on mobile → ✅ subPageId is populated.

Expected behavior

context.page.subPageId should contain the subEntityId value from the deep link regardless of where the link is clicked from.

Actual behavior

Click source	Desktop	Web	Mobile
Different chat / channel	✅ subPageId received	✅ subPageId received	✅ subPageId received
Target channel's own conversation	❌ undefined	❌ undefined	✅ subPageId received

[microsoft-github-policy-service]

Hi @lingfeidiewu! Thank you for bringing this issue to our attention. We will investigate and if we require further information we will reach out in one business day. Please use this link to escalate if you don't get replies.

Best regards, Teams Platform