[GAMEPLAY] Poppy not staying with target when using E

I've noticed a bug with Poppy's E since 6.1. When you E an enemy sometimes Poppy will not go the distance with the enemy champion and will stop while the enemy keeps going forward. Poppy is not being CC'd during the charge and the enemy is not using a dash or blink. And it does not matter if the enemy is going to get stunned against the wall or not. I've noticed it happening about once every couple of games. It has little impact if the enemy is going to be stunned against the wall, since you are still close enough to follow up, but if the enemy is not then they end up well outside of non-passive AA or Q range.

1. E an enemy champion.
2. Poppy will not follow the enemy for the full distance of the charge.
3. The enemy after the charge will be well outside non-passive AA or Q range.

I haven't noticed anything when it happens that would be in common, so I don't know what is causing this.