Agree so much with miroslav.
Other than that thought I'd chime in and say GM13 has a lot of random and seemingly unsolveable issues caused by nothing for people with no pattern to the problems, bugs, etc. themselves, sometimes they resolve themselves and sometimes they don't. It's not like 10 where sometimes the bug was caused by someone overlooking some minor detail or anything, it really does just come out of nowhere nowadays since Garry broke it, we really are still in alpha stages of GM13 at best and him calling it beta is just despicable. That said, it might be a while before this issue resolves, and more likely than not, it will simply go away on its own, not in an update, not because you managed to fix it, but because it stopped feeling like being stupid.