I've found the update to eat a lot into the battery but I believe it will be sorted out in a security update soon. Also it is still learning your usage patterns since the update so it will take a while to learn usage patterns.
I understand you. Only reason it hasn't powered off is because I wasn't using my phone much, but I mostly be pulling 8 hours on screen time with one ui 6.1 and my phone lasted whole day. Hopefully you're right and they fix it with a security patch.
