SOLVED Sync: strange behavior between devices

Mystery solved. I had an installation of Edge Stable on my brother's notebook, which he is no longer using. And on that Edge browser I had two profiles. I didn't even remember it anymore, I think it was a year since I did it, lol...

I deleted that second profile, and from then on everything is perfectly synchronized, in all installed browsers, and in the different versions (Stable , Dev, Canary...), the extensions that I add or remove from one are automatically applied in all other Edge browsers, as are changes in the bookmarks bar, etc.