Generally, code like this doesn't simply stop working abruptly on its own. At least not under these particular circumstances. My guess is it has nothing to do with my code but rather internal changes to GameMaker's macOS runner which doesn't play well with my extension's pre-existing code. Meaning, I didn't break anything, but YoYoGames did. This is something I need to make accommodations for quite a bit over the years, because they constantly break how my code interacts with theirs, forcing me to either file a bug report, (and hope they fix it), or be left with having to attempt a workaround to the problems they created, on my end, even though it isn't my responsibility to fix what they break.
That said, thanks for bringing this to my attention. I'll see what I can do to get this resolved.