In Glyphs 3 (3133 and 3137), there is a problem with paths that should be blanking out being filled in.
I am also attaching the Glyphs file that is causing the problem.
20220922_PathProblem_KK.glyphs (1.5 KB)
I hope this helps Glyphs users as it seems like a basic problem.
Thanks for the report and example case. That’s a bug. We’ll look into it.
I believe it’s been fixed and will be in a future cutting edge release.
I opened the file and appear wrong. 3137
Convert to quadratic and fix it
Convert to cubic again and still fixed.
My five cents 
Thank you Georg and etunni for trying this.
My mac is running on an Intel chip, could it work differently with Apple Silicon or Intel?
composerjk, thank you very much. It seems to be reproducible, so I hope it will be fixed.
It seems that the problem only shows on Intel macs. On my Apple Silicon mac, it works fine. We are looking into this.
Georg, thank you for addressing this issue.
I haven’t seen you since AtypI TOKYO, but I always appreciate Glyphs’ great thoughts and solutions.
