Microsoft 365 Alert – Service Degradation – Microsoft Teams – Users may be unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels – RESOLVED

04/09/2026 10:45:00 AM

NHS.net Connect Reference: INC46925755

Microsoft Reference: TM1466441

Issue Status: RESOLVED

Issue Description: Users may have been unable to access tabs beyond the Conversation tab in certain Microsoft Teams channels.

More info: Users may have only see the Conversation tab in Microsoft Teams channels when channel names and associated sensitivity labels were long, particularly on smaller displays. As a result, other tabs such as Shared, Files, Notes, and custom tabs may have not been visible.

As a workaround, impacted users could zoom out in Teams, use a larger display where available, or, in some cases, select the overflow arrow to access hidden tabs.

Final Update: 04/09/2026 10:47:00 AM – Microsoft has confirmed through testing with a subset of affected users that reverting the recent configuration change has remediated the impact.

Scope of impact: Any user attempting to access tabs beyond the Conversation tab in Microsoft Teams channels with long channel names and/or associated sensitivity labels may have been impacted.

Root cause: A recent configuration change associated with a user interface modernisation effort inadvertently introduced a regression that was preventing Teams channel tabs from rendering correctly.

Next steps: Microsoft is reviewing the offending configuration change to understand why the regression wasn’t identified during our pre-deployment testing processes, so that they can prevent similar issues from occurring in the future.