Severe battery drain on Release Candidate 13.21

Hi all, is anyone else experiencing significant runtime shortages since installing the latest RC 13.21? Before the update, I had an average battery consumption of sometimes well below 0.5% per hour (spend a lot of time in flight mode and then sync manually via Wifi). Since the update a few days ago, I consume, especially at night, sometimes >>1% per hour. I can only manage five days at most.

Does anyone have any advice?

Can I somehow drowngrade to the old SW?