Pixel users report battery drain issues after March update, and this could be the reason
(www.androidauthority.com)
I've just been having an issue where one of about 6 apps keeps running in the background even when it's set to not run in the background. It'll eat about 20% of my battery in an hour and a half and I'll have to force close the app. I usually notice because my phone will be in my pocket and it starts getting very warm.
Stock pixel 8 BTW.