[GAMEPLAY] Braum Ult not working on Random Intervals

I was playing a game as Braum when i got into a group fight. After i blocked ashe's ult(sort of...). and flashed away to safety. I could not use my ult. I would click on it and click. The ult Line would appear but it would not activate. After retreating and continueing to Spam R. It finally went off. I was not silenced or stunned throughout the duration. I also was using El Tigre Braum.

I was recording at the time and left the link in the post