Thank you so much for providing your .app, I was able to reproduce the issue here on my Mac. So the problem is actually due to a codesign validity check triggered because the FMOD bundle has been tampered with. The tampering is the line endings for the Info.plist file contained within fmodstudio.bundle and fmodstudioL.bundle. I was able to quickly fix it here by installing dos2unix via homebrew and running it on the file.
We ship the Info.plist files with Unix style line endings as is the norm on macOS, so I suspect the endings got flipped by your source control, possibly due to wrong settings, or possibly checking the file out on Windows, copying it to a Mac, then checking it in on the Mac.