Additional calendar-related features and issues within Microsoft Teams for business
Hi E78 Service,
Welcome to the Microsoft Q&A forum.
Based on your description, the issue occurs in both the desktop application and the web application. In addition, I can see that you have already performed several troubleshooting steps, including verifying the user's license assignment and reviewing the relevant settings in the Microsoft 365 admin centers.
In this situation, I recommend creating a support ticket with Microsoft Technical Support. They have access to advanced diagnostic tools that can help investigate the issue in greater depth and identify any backend service or provisioning-related problems.
To create a support ticket with Microsoft Technical Support, please refer to the following documentation:
Get support - Microsoft 365 admin | Microsoft Learn
Additionally, based on the information I found, Microsoft has acknowledged an ongoing issue affecting users who attempt to make changes to Teams, Channels, and Calendars.
Microsoft is currently investigating and working to resolve this issue. According to the latest Service Health update, the next update is expected to be provided on Friday, August 21, 2026, at 01:30 GMT+7.
You can monitor the latest information related to this issue by referencing the following incident ID: TM1458179.
I hope this information is helpful.
If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.
I look forward to continuing the conversation.
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