IPhone 12 pro and IOS 14.3

My new iPhone 12 Pro loses about 30-40% of battery charge overnight. Only Bluetooth(because of Apple Watch) and Wi-Fi are turned on. Background refresh disabled. The screen does not turn on due to sleep mode. I cannot contact the service(I'm in another country) and I'm sure the battery is ok. In the battery section, everything is zero. I mean 0 screen time and 0 running apps. I saw the same problem with someone here, and it says that perhaps this is because of iOS 14.3(his battery is 100% ok), and I hope that this will be fixed in iOS 14.4. But even with this problem, I have enough battery power for a day with normal use.