Guild Wars 2

I keep my kiting circles plenty tight yet right in the middle of combat they will suddenly stop and fast healing as they return back to their start position.

This is a blocker issue as fights that normally would be done now get reset 2-3 times roughly every six mobs.

I get this too, where the mobs suddenly start being invulnerable, which is especially annoying for veteran and champions, particularly when they aggro onto you as soon as they heal, since I generally stay right near their spawn spot.