Hi @Lars Kohsel ,
Thank you for posrting in this community.
It seems this is not a common issue per my test. Everything is fine in my environment. However, we can work together to narrow down and resolve the situation. My guess might be because of synchronization issues.
1.Test on a different computer: Log in on another computer with the problematic user account to see if the problem persists. This will help determine if the problem is user-specific or a computer synchronization issue.
2.If it's not a synchronization issue, try updating and patching: Make sure that both SharePoint and Word are up to date with the latest patches and updates. Sometimes, issues like these are resolved in newer updates.
Hope the information can help you. And if there have any unclear or misunderstanding, please feel free to post back and we’ll continue to help you all the time!
Your understanding and patience will be highly appreciated! Hope you have a good day and keep safe!
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