I am an IT consultant (have been for nearly 30 years). This was relatively easy to solve. I had a client with multiple users experiencing this problem. After some troubleshooting I found two possible solutions depending on the mood of the computer: 

1) delete and recreate the outlook profile - resolved on some

2) delete and recreate the windows user profile - resolved for all 

Number two is much more intense depending on how your computer is setup. All my clients are domain-joined so I just logged in as administrator and deleted the user profile and then recreated. This resolved on all no matter what. I would try number one first (for sake of speed) and it resolved probably 40% of the affected users. 

Also, we did not start seeing this until recently (Fall of 2022). Therefore, I cannot determine what actually causes it. We keep Windows, Dell drivers / firmware, 365 and QB updated with great frequency (pretty much monthly or every two weeks) and, again, just now noticed it. 

Hope this helps!