Battery drain (iPhone 15, iOS 26.1)

Battery drain (iPhone 15, iOS 26.1)

Hello there! After the last update my phone started randomly rebooting at around 50-60% and when it loads it shows that I've only 10%, even though it was around 50 before. My battery life is at 90% and before the update my phone would work for around 7-8 hours while using mobile data and VPNs, but now it's just a nightmare.

I've factory resetted my phone and I've also tried hard reboot but nothing works. I wonder if anyone is experiencing the same problem as me.