Strongbox Rubberbanding

I died 5 times today to the same 'bug' or whatever you want to call it, and the situation's becoming beyond infuriating.

Whenever I open a strongbox, my character starts rubberbanding as if I have insane ping. I don't, though, because I've monitored it before and while the rubberbanding was happening.

It's always the same: I open a strongbox and start moving away from it and try casting spells, but all my character does is move 5 steps in the direction I'm moving to and then teleports back to the same place, right next to the strongbox.

It doesn't cast any spells, and it doesn't move any further than those 5 steps. And the character just keeps rubberbanding like that until I die.

While I'm rubberbanding all over the place, the rest of the world works normally. Monsters from the strongbox keep spawning, and the ones around it do what they usually do. Eventually, I just die because I can't do anything.

I don't know if it's a specific strongbox type that causes it, but it always happens whenever I open a strongbox.

It's not a PC issue for sure. Well, at least it's not a hardware/spec problem. I do juiced Abyss maps, and I've no issues with performance even when there are significantly more monsters on the screen. Other than random crashes, but that's another issue :p