When a modal frames is showing its scrollbar, hovering add a blur effect:
Thanks for reaching out! I haven't been able to reproduce this yet 
Are you still seeing this issue? Any chance you can share an app export?
What browser/device are you seeing this on?
We found and fixed a bug where modals in modules could become blurry 
hope this solves your case!
A post was split to a new topic: Modal Frame Blurry