There is currently a glitch that may be exploited with Poppy (and possibly Annie).
Here is a video demonstrating the potency of this:
The exploit originally used HexaFlash. However, workarounds have been figured out already. Poppy can still do this with Flash. A video showing it done here:
I am not sure if it has been fixed completely yet. I realise most people wouldn't use their main accounts to do this as they will likely be banned in the future. However, this has been used in SoloQue which is causing LP loss for the unlucky team that goes against the Poppy. Additionally, the first video shows at least one person being banned for "intentional feeding" because they were unlucky enough to go against this.
I just wanted to give the heads up. A few of my friends are taking a hiatus from SoloQue until word comes out that this is completely patched.
Best wishes and I hope everyone stays well!