A family of Microsoft word processing software products for creating web, email, and print documents.
Dear Gianluca Maccagni,
Good day!!
I understand your concern and tested the behavior in the teams for the web, where reproduced the same behavior and the problem is not related to the specific browser because I have tested the behavior in a different browser and had the same problem.
However, when you open the same Word document in the browser, we can insert the picture from OneDrive/SharePoint sites without any issues.
So, when you open the Word document in teams, click on Editing> click on Open in Browser> Insert the picture from OneDrive.
Moreover, report the behavior to the related development team via adding the feedback in the Teams for the web. Click on the Help in Teams for the web> Give Feedback
Thanks for your patience and understanding.
Regards,