Cassiopeia R animation. Gameplay.

Been playing Cass recently and on occasion her R fires the animation completely off the hit box. Example, Fleeing for life from a chasing team. Using hot-keyed R fire ulti behind me. The animation fires off in the direction i was moving but all enemy champs behind me are stunned and take damage. Its something that's happened in multiple games (to a varying level of inaccurate animation.) and as of yet I have been unable to recreate it (tested few things in 1v1 with bot.). My personal observation is it occurrences more frequently mid to late game after build has come along and am over 200 stacks of passive. Items tend to be boots upgraded with furor, rylas, wota, Tear. I have qwer all hotkeyed to smartcast, and have the distance indicator enabled so i can hold fire on skillshots. Has any one else seen or reported this issue? Figure its due to a small animation canceling command input due to panicked spamming, part of the Cone bug riots dealing with, something to do with MS or Cd, Or the number of targets R hits. If any one else has information please let me know. save me some trouble. Gl hf yall.