Moritz, I went through this exact problem too and upon reviewing my video, my pushaway was very exaggerated to the right just as Brad mentioned.

Dustin Smith thank you Dustin! I was kinda under the impression that your grip should be almost nothing, I've stopped trying to achieve that and instead get it to 20-30% and had a decent first night out in league. I actually think my thumb was bruised under my skin which is why it hurt so much even if I held it by my side. It doesn't hurt at all anymore so now I will just try to dial in the thumb tightness with different tape configurations.

Dustin, thanks so much for taking the time to reply. I've applied for the Facebook group so in the meantime while I wait to be approved I'll ask this quick question - do you build tape up in the thumb to press your nail against the back or build tape to press the thumb pad down? Or maybe in the middle 😂