bios – Computer doesn’t POST after enabling Secure Boot

I wanted to turn on the Secure Boot so I can check if my PC Is compatibile with Windows 11. In order to do that, the BIOS asked me to choose a “Protocol/Publisher/Platform” key? I don’t remember exactly. I choose the default one (808 pk I think it was), and then to disable CSM Support. Now it doesn’t boot! The display is black and the keyboard leds flash on and off.

I tried everything I saw on the internet. I reseated the CPU, the RAM, the GPU, I disconnected the the drive, I connected an (older tbh, 10+ years) drive, I used another (again 10+ years old) GPU, I reseted the BIOS with the jumper, I plugged out the CMOS battery, I left away over night.
Specs:

  • CPU: i3-10100f
  • GPU: GTX 1650
  • PSU: Elementium Silentium E2 550w 80 Plus
  • Motherboard: Gigabyte H410m s2h
  • Memory: 1x 8GB DDR4 2666mhz (HiperX Fury CL16)
  • Storage: Western Digital Blue 500GB, 7200rpm