Created breakout rooms for a meeting, when rooms were opened, participants were unable to unmute themselves.

Dear @NadT,

Thank you for posting your question in the Microsoft Q&A forum.  

This issue is typically not a general Teams service problem but is most often related to the specific settings configured for the meeting. The permissions set in the main meeting room are often carried over to the breakout rooms. 

Here are the most common cause and the steps you can take to prevent this from happening in the future. 

The most likely cause is that the option "Allow mic for attendees?" was disabled in the meeting settings. As the meeting organizer, you can control this permission before or during a meeting. 

1. Before the Meeting Starts: 

• Open your Teams Calendar and double-click the meeting to open its details.  
• Choose "Meeting options". 
• In the settings pane, find the "Allow mic for attendees?" option and make sure the toggle is switched on (blue). 

• Click Apply. 

2. During the Meeting: If you notice the issue is happening live, you can change the setting immediately: 

• In the meeting controls, select More actions (...) > Settings > Meeting options. 
• Toggle "Allow mic for attendees?" to the on position. 
• Participants in the main room and breakout rooms should now be able to unmute themselves. 

For a detailed guide on managing these permissions, please refer to the official Microsoft Learn article: Manage attendee audio and video permissions in Microsoft Teams meetings - Microsoft Support 

If only one or two participants are affected, you can manually enable their microphones from the "Participants" list. Find their name, click the three dots (...), and select "Allow mic." 

3. Restart the Meeting: Sometimes, simply restarting the Teams meeting can resolve unexpected issues. Ask participants to exit the breakout rooms and have the organizer close and then reopen the breakout rooms. 

4. Update Teams: Make sure that all participants are using the latest version of Microsoft Teams. This can help to resolve any bugs or issues present in the app. 

For a detailed guide on managing these permissions, please refer to the official Microsoft Learn article: Update Microsoft Teams - Microsoft Support 

If the problem continues, it may be helpful to check the Microsoft 365 Service Health Status for any ongoing incidents or report the issue via the Teams admin center for further investigation. 

(Please note that if you are a user you will need to ask your global administrator to perform these steps) 

I hope this explanation is helpful. Please let me know if you have any other questions.

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Hi there, thank you for your response. Allow mic for attendees?" was checked to the on position.  Bu the issue still persists. Any other suggestions are welcome. Thanks.

Dear @NadT,

Thank you for following up and confirming the meeting settings. I understand your frustration, and I apologize for the significant disruption this caused to your meeting.

Based on your detailed description and the timing, this incident aligns precisely with a known issue our engineering team has been actively investigating under the reference TM1134560.

Summary of the Issue (TM1134560):

• Impact: Users, particularly those in cross-cloud or anonymous join scenarios, were unable to unmute their microphones during meetings where recording was enabled or in breakout sessions.
• Scope: This was a service-side issue affecting a subset of users.
• Status: The targeted remediation for this issue was deployed, and it was officially resolved as of August 26, 2025, at 4:42 PM UTC.

Recommended Action for You:

Since the fix has been deployed, the first step is to confirm you are on the latest version of the Teams client and test the functionality again.

1. Update Teams: Please ensure all participants completely quit and restart the Microsoft Teams application. This forces the client to update to the latest code that includes the fix.
2. Test: We recommend scheduling a brief test meeting with a few colleagues to create breakout rooms and verify that the unmute functionality is now working as expected.

Additionally, we recommend reporting this issue directly to the Teams product team by navigating to: Settings > Feedback > Report a problem Your company’s Global Admins can also report the issue in the Microsoft 365 Admin Center via Service Health, as shown in the screenshot below. 

As a community moderator, my role is to provide guidance and known solutions. I have escalated this thread for further visibility, but I do not have direct access to your tenant's logs to investigate further. For a deep dive, opening a support case with the above information will allow the dedicated backend engineering team to investigate your specific environment.

I appreciate your patience and understanding as we work to ensure Microsoft Teams operates reliably for you.

 If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".   

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