Hi @R
Welcome to our forum!
Does the issue occur recently on Outlook Desktop Client? Do you have any specific operation before the issue occurred?
To further confirm if the issue is more related to Outlook desktop client, if possible, please log in to your web mail and do the same test to check if the issue persists.
What is the version of your Outlook? It is recommended that you please check the Outlook client version (File>Office Account>Product Information) and try to upgrade to the latest version to see if the problem is resolved.
In addition, it is suggested please go to File>Options>Calendar>untick Show Meeting Insights box to see if there is any difference.
Hope it helps!
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