Therefore, I have decided it again with a different DP cable to try. I (3-fold shielding), Purelink (Certified) and Assmann (DP1.2 compliant) wavered in my decision betw. The models of Jou Jye. At the end I was convinced of the Assmann product the detailed data sheet and the price.
The plugs go much easier in the bushes and the hook to Verrigelung are smoother than with my old cable. The video transmission will now work properly, the transmission of audio, I could not test. I am very satisfied so far.
DIGITUS ASSMANN ANSCHLUSSKABEL DISPLAYPORT AWG30 2XGESCHIRMT BLACK, AK-340100-020-S