Yeah, you're right, my S26U wasn't even a month old and it was having battery issues with the new update. Even in power-saving mode, and even when the phone was idle with the screen off and no always-on display, it was draining about 10% battery.
Me too brother i was getting around 10 hour+ battery backup before beta update and it was draining battery more rapidly when the screen is off, even in maximum powersaving