Devour Movement Paused/Stuck

I've been playing Kayle jungle since season 4 and when I started using the new devour I get sporadic movement loss and pausing. I lose control of Kayle and my mouse commands do not work. I have tested on another PC and same issue. When I play Kayle without devour i do not have this issue.

Another issue I've seen with devour is that it reduces attack speed randomly, after 3 or so seconds it will go back to normal.

I've been playing this way for 3 weeks and have not found anyone else with this issue. I am hoping someone can help with it; thanks in advance.