Windows iTunes: iPhone disappearing after a split second or not showing at all

Hello,

today I tried to create a backup of my iPhone 12 Pro max using my PC (Windows 10 64 Bit).

However, after I tried connecting it to iTunes, it only showed up for a split second, and then disappeared again. Another time, it just stayed greyed out. The explorer opened up showing that it was connected though. I reinstalled both, the Windows Store and the Apple Website version, but nothing changed. I also tried restarting the Apple Drivers, but I didn't achieve any positive results.

I am desprite.

Might you know how I could fix that?

Thank you in advance!