Serious Bug needs fixing Sions ult vs Thresh's hook/ Hook wins every single time.

Here's the problem Sions ult vs Thresh it doesn't work i mean the ult actually breaks to the hook, I've tested it 4 times in one game. its broken literally broken its bigger then a glitch. if Sion while ulting gets hooked by thresh in a head to head charge, near the end of his ult. thresh is given immunity to Sions ult he takes no damage does not get stunned and stuns Sion immediately after the ult ends for no reason. its very BROKEN. not only this but 30% of the time if u activate an ability as Sion after the ult in that stun period it will break the skill. as in you CAN NEVER USE IT AGAIN!!! the skill stops working u can spam Q for weeks and it wont work u have to restart the game to fix this. sometimes more then once.