I have a friend with a bad broadband connection (2Mbps max I think, varies). He often experiences desync of 100000 in the player list and when that happens other characters disappear to him, he can't open doors etc. Interestingly sometimes other players around him seem to have rubberbanding, hard to say for sure as it is so random.

I read somewhere that someone thought this was caused by containers. My friend does have a lot of protector cases so he decided to drop them all. As soon as he did so and we moved away, the desync and rubberbanding stopped almost completely.

To try to see if this was just random he then logged in to a hardcore character (holding 7 protector cases) to try the same thing. As I ran with him to drop the cases we both constantly rubberbanded back to the start of the field we were crossing. Once we got to the treeline and he dropped the cases and we moved off neither of us rubberbanded for the rest of the session.

Since dropping his protector cases my friend has no longer experienced a level of desync that significantly affected game performance.