This is a bug with the masking not working for patterns. Basically, your computer can't handle the processing.
It is something however, that can be fixed! Unfortunately we're unable to test out any fixes ourselves, as we don't run into this issue. If you are willing to lend us your support, we can try and patch up the bug, have you test it to see if it still persists, and continue working on a patch that fixes this issue. We do need your cooperation though :)
Please join the Discord and let me know in the #techsupport channel that you're available to bug test with us! I'd like to squash this bug.