A fully upgraded ice spike ability can hit the same enemy 4 times, this happens because in the right position they will be hit by the initial trail of small spikes, the large spike and two of the additional spikes which spread out from the large spike.
its not a bug, did you even try to land it? Normaly it hits for 2 or 3 Hits only, because this is the perfect scenario which needs you to hit the spike in the middle of your charecter. but i saw your other “teleport” thread where you just lagged. It seems you are annoyed by the IG.
Enemy gets hit once for the trail, once for the big spike, and twice for the 2 smaller projectiles that come out of the big spike. all-in-all thats 4 different procs of damage. This is 100% working as intended and not a bug