
Hi @Alessandro ,
Welcome to Q&A forum!
- Was there any error message when this issue occurred? If yes, please describe it in detail or share a screenshot with us.
- Do Word and PowerPoint also have this issue?
- When did this issue start? Have you installed any other third-party software before? Such as, third-party Add-ins.
According to my research, some incompatible third-party software of Mac may cause this issue. Please disable or uninstall them to check.
It is also recommended that you try starting Mac in Safe Mode so that we can rule out third party programs interfering with Office startup:
How to use a "clean startup" to determine whether background programs are interfering with Office for Mac
Any updates, please let me know.
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.