Rumble Ult Not Going Where Placed When Getting Out Of Zhonya's

At first I thought it was just me missing, but then it just kept happening. I was in zhonya's invincibility and had my ult ready to go off right on top of me once I got out, and once I got out it didn't go there at all. It treated the spot that I wanted it to end as the beginning for it and went in a straight line away from me. As a Rumble main who loves to abuse Zhonya's, this is kind of screwing me over. Hopefully someone else can check this out.