I am reposting as the original thread had a incorrect example.
Here is a video showing the issue: https://www.dropbox.com/s/izdyroakbm7bx43/bandicam%202021-03-13%2014-58-27-103.mp4?dl=0
As you can see there is no masking or polygroups yet I am unable to paint on random parts of the mesh. This has never been a problem prior to 2021.6. You can also see that some parts can be painted on if I smooth it first. Really weird.
Did anyone run into this issue? Any idea what else might be turned on that can cause this? I’ve reset UI to default to make sure but it’s still happening.