[GAMEPLAY] Sion stops attacking after using Q

I've noticed lately that Sion will almost always stop attacking his target at some point after using his Q. For example: he hits a champion with E. Afterwards, he charges Q long enough for a minimum duration knock-up. Then the player right-clicks his target. Sion will start attacking the target, but will stop after a swing or two.

This is very noticeable especially when doing something like attacking a turret. If Sion has a sheen item, he may use his abilities to get extra damage on the turret from sheen procs. After using Q, he will shortly thereafter stop attacking, and the player will have to right-click again.