[GAMEPLAY] Vel'Koz ult not working with spell combo

In the body of the post, include a more in-depth description of the bug you are encountering:

If you quickly cast your other spells and then use R, sometimes Vel'koz will simply not use his R.

Follow up the description of the bug with numbered step-by-step instructions on how to reproduce the issue.

Play Vel'koz with all spells up, quickly use QWE (idk if order matters) with R last. Expected result: All spells are used as with cast times queued and executed. Actual result: QWE all work but R does not cast or animate.

Include how frequently you can get the issue to occur and any video or screenshots of the bug that might help clarify it:

Happens about once a game or so, I can't reproduce it with any consistency but it happens frequently.

Notes: Possible relation to other Vel'koz ult bug where Vel'koz animates his ult (immobilizing him), but does not cast it?