remotecontrol plugin not working in nDisplay/Switchboard 4.27

I don’t get anything to happen with OSC, DMX or Webremote messages inside nDisplay. Everything works fine in the Editor. I just use a RemoteControlPreset. But also tried with an OSC Blueprint (which works in nDisplay in 4.25 and 4.26).
IP and Ports in Switchboard preferences should be fine, Firewall turned off.

Has anyone a clue what I did wrong? It works fine for others.