My programmer recompiled and reuploaded the mac file. Redownload and it should be working as expected now!
For Reference’s sake:
So I had my folks look into this more, and it looks like there was some compiling issue that’s breaking the default macOS unzipper. Using a third-party unzipper (they were using https://theunarchiver.com/ ) works just fine, which is why we didn’t catch it initially.
So that’s a temporary solution in the event this happens again. But it looks like a simple recompile on our end fixed it with default macOS.