After updating to macOS Sonoma and Sketch 98.3 (on a Mac Mini M1), I have troubles resizing shapes that were rotated. I’ve posted a screen recording below.
Basically, once that rectangle has been rotated 90º, I have troubles grabbing its corners with the free resize cursor (diagonal arrow).
EDIT: it happens with groups too.
Hello @tudor 
Thanks a lot for the feedback. We are currently fixing some errors with Sonoma, so we genuinely appreciate your input.
I’ve tried to reproduce this in Sonoma with a Mac Mini (M2 Pro), but I haven’t been able to. One thing to check, if you have plugins enabled, is to try to reproduce the same behavior in Safe Mode.
After that, if you are still experiencing the same and you are willing to help us, perhaps you can reach out to productsupport@sketch.com, and we will troubleshoot this further.
Also, I wonder if anyone else out there is experiencing this issue!
Cheers! 
Indeed, it looks like a plugin (Deck) is the cause of this issue.
Thanks!
Oh, thanks for the information!
I guess that they will have to adapt the plugin to Sonoma! Perhaps you can give them some feedback here.