[Help - Other] Weird Quest glitch

I'm having the exact same problem this guy is/was having, (https://freestylersworld.com/showthr...nection-glitch) but I thought I'd add more information to demonstrate just how peculiar this glitch is.

The problem:
A significant portion of enemies (and sometimes bosses) in quests don't appear to move from their original location. That enemy is actually walking around the room trying to attack people but cannot hurt me. The enemy that I see (still stationary) can totally damage me if I get anywhere near it.

Interesting info:
-I'm playing with two other people on the same wifi. One of them experiences the same problem I do, while the other does not.
-Both of them are playing on windows 10 on windows-native gaming computers, I'm playing on windows 8.1 through bootcamp on a mac.
-I experienced the exact same problem when I tried to play gunz at Gunz: The Last Duel (except there, bosses glitched 100% of the time)
-The glitch does not occur when I play quest mode by myself.
-Glitch still occurs when wired directly into the router.

I've restarted, reinstalled etc. I haven't tried port forwarding or /forcenat yet but none of those things worked for the guy who was having the same problem as me. (Link at the top) I don't know if any of the information I've provided will help find a fix for this problem, but it certainly is odd. The fact that a windows computer is having the same problem shows that it's not my mac's fault, and the fact that I had the same glitch on a different server makes it seem like the problem is in Gunz itself. Or maybe it really is a router problem? It's really frustrating though, so help plox.