[Gameplay] Lulu causes enemies to leash incorrectly

As Sion, I bought Talisman and 3 pots, and went to Krugs. I was blue side, so I had my bot lane, Lulu and Vayne, help me do Krugs. I started charging up Q, so that it was max power when they spawned; when they spawned, I released Q and smited them, while Vayne and Lulu autoattacked them. However, for some reason, it wasn't leashing correctly; it spontaneously lost patience for no reason. Even when I was right there, attacking it, it would lose patience as it attacked me; it eventually leashed. I noticed the patience drops were most often when it was stunned, from either the Krugs smite bonus or my Q. I eventually ran out of health pots, so I had to do red then back.

I think it might have something to do with Lulu; when I did red and came back to it, Lulu was also coming back to lane, and helped me out with an autoattack. The monster immediately turned and started chasing Lulu; I had to smite him to prevent him from leashing again. I just checked in a custom, and it seemed to be working fine with just Sion solo.