Two simple setups.
Chamsys MQ80 + VDMX + Luminex DMX4 MKII + network switch
everything works. Like DMX to Video and so on.
Grand MA2 + VDMX + Luminex DMX4 MKII + network switch
in every few seconds DMX input fails.
If I leave only Grand MA + VDMX, everything works.
It seems like a network error, but I do not see any difference between Chamys and Grand Ma.