has anyone else noticed a bug causing you to miss gold by minions ?

this is happening to me for a quite long time now but for most of the time I thought it's just me missing the CS but technically It's impossible.

So im a main, missing CS with her is hard due to her E. So the bug I think i have quiet often is that I press E, get the CD and Mana refund meaning it was a last hit, but missing the gold and the CS count, how is that possible ? It doesn't only happen to me with Kalista but also with other champs but with Kalista I can be quite sure I did last hit it because of the E CD and mana refund.