Now I have downloaded Global firmware instead of EU firmware and it was ... sucessful
Downgrade was also successful.

Starting phone
Connecting to the PC via USB
Starting MsmDownloadTool
Windows11 Pro:
cmd [enter]
adb devices [enter]
adb reboot edl [enter]
phone screen is black
MsmDownloadTool: Connected. Clicking Start, then downgrading successful.
Thanks for you support

(I have bought the phone in the EU, but had to use the global firmware)