iPhone 15 battery drain fast

6 days ago I sold my iPhone 11 device and bought an iPhone 15 128GB. After transferring the device, the battery drains very quickly. I get almost the same screen time as my iPhone 11 device, while it is observed for approximately 7-8 hours in the tests made on the internet, on my phone it lasts 4-5 hours, and when I turn the device on and off, my battery is 2% decrease . When i using Instagram, my battery does not drop at all after using the application. When I look at it 2 minutes after locking the screen and putting it aside, there is a 1-2% drop. On my device, background application refresh is turned off, automatic brightness is enabled, location services are set only when using or never, apple support every time I connect. After the tests he made, he said that my battery was normal and there was no need for service, the device was calibrated, but I was very upset that the battery drained so quickly. What can I do about this situation? Is there anyone who has experienced it?