I'm actually starting to wonder if part of what fixed it for ME was some kind of sorcery that occurred when I opened Detective Grimoire on a system that RAN 32-bit before bringing it over-- creating two different boot-types. When I clean-install Detective Grimoire, I don't get the "Detective Grimoire" and "Detective Grimoire_32" thing. So strange! Just don't want to be reporting something that doesn't work, should the occasional macOS user come through. At any rate, two other good solutions for fixing all 32-bit Adobe AIR games:
1) Steal the shell of a 64-bit Adobe AIR game (like The Last Door Season 1 or Season 2... or, like, The Floor is Jelly, which was included in the Itch.io Bundle for Racial Justice and Equality), then right-click > Show Package Contents and go to Contents > Resources, and delete all the files in that Resources folder. THEN go to the Resources folder in the 32-bit game you want to play, then transfer all those files into the folder of the 64-bit game. This seems to work super-well with all DRM-free games-- I've even gotten this to work with PC Adobe AIR games!
2) Build a 64-bit Adobe AIR shell yourself using Adobe Animate/Flash and the free Adobe AIR SDK. Build, like, an empty Flash file, build it as an Adobe AIR app, then replace the Resources again. Good times!