You wouldn't have seen it in tests because you didn't test with firejail. I've mentioned that firejail is a sandbox program, which is a program that isolates programs for security purposes. https://en.wikipedia.org/wiki/Sandbox_(computer_security)

I tried turning it off, but it still does it, which seems strange.

>  If you can figure out what Unity wants from Firejail, I think that's your best bet in solving this issue.

I've been trying... which is why I've been asking you what dependencies you have.