Annie Stun Bug (Not Applying randomly) [GAMEPLAY]

Playing ranked an an alt account, got rolled into off role, picked annie. During lane phase my stun was charged and multiple times I've used it on the enemy diana, it's hit (q and R both) and not applied the stun, allowing them to turn around and kill me. I died three times purely because of RNG stun not applying. By the time the diana was able to dive me, I sat on my passive stun with ult up hugging tower and last hitting - I got dived twice in a row in the exact same way, ult-stunned on top of the diana and didn't apply stun. Talking with the enemy diana who noticed it too, we tried to recreate it on video but the teams kept interrupting for easy kills because soloqueue, the few chances we got stun applied, but during lane phase it seemed to be 50/50 at best.

The obvious 0/10 annie game has a recording on OP.GG, can see it not apply several times in lane. This is game destroying and elo-breaking. It removed any potential to counterplay the diana - once she got the lead I couldn't do a damn thing to stop the free dive. Without her passive annie is a useless champ - if this bug isn't a one off random malfunction (if that's even possible) then she has to be disabled and hotfixed.