Jax Ult is bugged

I was in a ranked game just now and I was Jax fighting top against Gangplank. As soon as we hit lvl 6 six, I went for the all in and when I clicked my ultimate, it died off after about 1 second. The skill description shows that it was suppose to last 8 seconds. My fellow enemy team was working with me at this point after I noticed this bug and we at first thought that his ult died after being hit, but it turns out it dies out immediately, even without being hit. I played Jax in a custom game right after to see if I could recreate this, and of course, his ult dies out after about 1 second. It shows that it activates, but it ends much too fast. Please fix.

Edit 1: Looks like the stats still change but the animation disappears.