Anyone found a solution to YouTube draining the battery yet?

Battery went from 80% to 0% in about 6 hours last night while I was asleep. I've always used YouTube on background while my phone is connected to my bluetooth speaker.

I play an 8-hour Brown Noise video offline while I sleep every night. Wi-Fi is turned off, battery saving mode is on, mobile data is off, dark mode is on, and l've never had this problem before except in the last two days when my battery went empty while I sleep. Usually it would only consume 15-20% of battery during the 8 hours.