Would you be able to send through a photo of the Unsupported Signal error that you’re getting when you’re booting (I suspect that you’re just booting from Bullseye Raspberry Pi OS). Although if it is just the Unsupported Signal “Blue screen of death”-style on your display you can just let us know instead of uploading an image.
Nearly every time this is because the resolution that the Pi is trying to output at isn’t supported by your display, or the HDMI cable being used has some damage to it, although the bootloader error message may be at a lower res that is supported by the display and as such it appears
As seen in the RPi docs below, can you please modify config.txt to include the line hdmi-safe=1.