teams is dropping calls on MacOS after redesigned call

Test the next call in Teams for the web and compare it with the Mac desktop client; if only the desktop client freezes, clear its cache and have the Teams administrator collect diagnostics for build 26289.204.5281.6363.

Build 26289.204.5281.6363 is listed as the November 5, 2026 Mac release. Microsoft’s version page does not document a known freeze/drop regression for that build, and the page is historical version information rather than deployment or incident status.^1^

Isolate desktop client versus call path

1. Join a comparable call through Teams for the web at https://teams.microsoft.com/ using Chrome or Edge.
2. If the web call remains stable while the desktop app repeatedly freezes and reconnects, concentrate on the Mac client rather than repeating Wi-Fi testing.
3. If both clients fail, ask the Teams administrator to inspect the affected sessions because the problem may be in the media path, account, device, or service.

During a desktop call, open More actions (…) → Settings → Call health. Record or screenshot the values immediately when the freeze occurs. Call health updates every 15 seconds; useful warning signs include:

• Round-trip time: above 200 ms
• Received packet loss: above 2%
• Received jitter: above 30 ms
• A sudden drop in send/receive limits or video frame rate

These metrics distinguish a transport-quality problem from a client freeze where network measurements remain normal.^2^

If only the desktop client fails

Clear the Mac Teams cache:

1. Fully quit Teams using Teams → Quit Microsoft Teams, or right-click its Dock icon and select Quit.
2. In Finder, select Go → Go to Folder.
3. Enter:

      ~/Library/Application Support/Microsoft/Teams
   

4. Delete that directory, reopen Teams, and sign in again.

This removes cached Teams data such as thumbnails, local message history, display images, and add-on cache; it does not uninstall Teams.^3^

If the desktop-only failure continues after clearing the cache, uninstall and reinstall Teams as the next client repair step. Avoid manually installing an older build unless Microsoft Support or your organization’s Teams administrator provides an approved rollback path.

Administrator investigation and escalation

Because the behavior began after the update and occurs on two separate Wi-Fi networks, provide IT with:

• Exact Teams build and macOS version
• Timestamps and time zone for at least two affected calls
• Whether Teams web was stable
• Call-health screenshots from the failure
• Whether the whole Mac lost connectivity or only Teams reconnected
• Headset, camera, dock, VPN, or security software in use

An administrator can open Teams admin center → Users → Manage users → select the user → Meetings & Calls, select an affected session, and inspect its participant and telemetry details. This experience applies to Teams calls on Mac and requires a supported Teams administrator or communications-support role.^4^

They can also go to the user’s Client health tab, select the Mac client, and choose Request client logs. Remote collection supports Mac and includes calling, Web Media, shell, and SlimCore media-stack logs; collection can take up to eight hours.^5^

If call telemetry shows normal network metrics but the logs repeatedly show the desktop client failing on this build, the administrator should open a Microsoft 365 support case and attach the affected timestamps, diagnostics, and web-versus-desktop comparison. That is the evidence needed to investigate a possible build-specific regression rather than treating it as another Wi-Fi issue.

References

1. Version update history for Teams app deployments - Office release notes ...
2. Monitor call and meeting quality in Microsoft Teams
3. I can't reconnect to Microsoft Teams | Microsoft Support
4. Monitor and troubleshoot Teams meetings and calls from the Teams admin center
5. Diagnostic logs for Teams Client