I know, why does apple make it so hard, and it’s only getting worse :( I was going to ask if you tried the quarantine terminal command, but I see even my own upload doesn’t work on my own machine when I download it back from itch (whereas the preupload works fine). Let me do some research to see what other hoop we clearly need to run through now, used to be the terminal quarantine command was enough…
Alright, I’ve sorted it out (at least for myself trying to download and play my own game, what a concept).
I had to reexport with this setting enabled:
Then it turns into “You can’t run bcuz maybe malware!” in which case the following command then makes it work:
sudo xattr -rds com.apple.quarantine Escherport.app
So maybe you have an equivalent setting to enable sandbox support?