Hi Palafo, and welcome to the forum.
If you search the Scrivener for macOS threads for either Tahoe or Scrivener 3.5, you’ll see a number of posts about various bugs and workarounds.
I’ll point specifically to this post by our founder and macOS developer, noting the bugs he’s encountered with macOS 26 Tahoe.
Earlier in that thread, this post by our Head of Support notes some issues as well.
I tend to get most of my software from small companies, and I’ve seen those developers say they’ve encountered similar issues with readying their software for Tahoe. Since that’s the case, I’m personally holding off on that upgrade.
Many users have upgraded and aren’t seeing any issues at all. As with so many things in life, your experiences may vary.