It is apparently due to my computer, no matter which port it is, as long as it is not the main HDMI port, it does not recognize the screen. I've tried several times to connect my laptop or Huion tablet to the PC with the HDMI 2 connector, but it doesn't work. No sound, nothing at all. In the settings you can press detect 100 times, nothing happens. It is also not due to the drivers, they are all updated.
What else can I try to make it finally work?
Maybe try using a DVI or Display Port cable. Of course only if the PC and monitor have such connections.
Thank you, I ordered a DVI to HDMI cable, hopefully it will work then.
I keep my fingers crossed.