When using Dragon Tail on the Assassin and attacking with it repeatedly multiple times in a row causes rubber-banding. This is most evident by the fact that enemies don’t take damage and my mana keeps going up and down because I the client is thinking the kick has gone off while the server thinks the opposite so the mana is immediately refunded.
I’m on a 7fpa dragon tail kick. Basically to easily replicate this, just hold shift and cast Dragon Tail. What it looks like is bizarre - like a mixture of Dragon Talon but no damage is done and mana keeps depleting and then gets refunded.
This has been the case since D2R launch.
Found a previous report on this issue here Dragon tail weird stucking in enemys