huge DMX problems

Hello friends,

I've had two really big problems with my Hog 4 setup.
2x Roadhog4 with a DP8000 - Artnet node and a few Direct DMX outputs on the DP, as well as an Arkaos Mediamaster

The problems with the current HOG4 OS 3.12.0 started - but also downgrades up to 3.9.0 did not do much to solve the problem. It got better, but did not go away. And if the lamps jerk ... does not look so fragrance.
So I did not build and use something like that for the first time. But: There was no clean DMX signal from the Hog 4 system. What was really -Ssch *** E- and of course is - and especially new to me. I have tried a lot, the DMX tester plugged in and checked everywhere. It comes out everywhere FLICKER. This can not be.
About a backup switch was a GrandMA 2 as a guest console involved, of course, physically separated by the switch - of course, of course, oh another IP. Once the good has delivered the DMX - no * fucking * problem.
The problems also started when I had not even unpacked the grandMA.

Does somebody has any idea?

Greets Fritz