Battery drains so fast after upgrade to iOS 15.3.1

Mine is iPhone 6S. I just got new battery replacement at Apple Store on January 15. Then iOS upgrade to 15.3.1 sometime after that kills iPhone. It drains so fast. By my typical usage, I don't have to charge until I go to bed, but I had to charge at 9-10am, then afternoon, then evening. My battery health (max capacity) is still 100%.

I believe this is something to do with iOS 15.3.1. Apple needs to investigate and fix this issue. Seems like many people are facing this issue.