This is funny. I tried it once and didn't see what the benefit was. Then, when I tried to reset it back to normal git, I realized that the devs had not (at the time) made any clean way to revert it back, just a one-way conversion to jj. I haven't tried it since.
Jujutsu doesn’t change your Git repository in incompatible ways. It just tracks extra information in the .jj/ directory. There is zero migration needed to revert back to Git – you just start using Git again.
What were you trying to “revert back”? You should have been able to just stop using jj, there’s nothing to revert back to. It’s also possible that I’m misunderstanding what you mean.