Only Hue Bridge get´s timeouts on LAN port of Omnia AP

I am in need of some help with the following problem:
My Omnia (TOS7.2) is atm serving as an AccessPoint, connected via WiFi as a client to my router, and via relayd all clients connected to it´s LAN ports are integrated into the home network.

All clients connected to the lan ports of the omnia - except the philips hue bridge - are working well. The bridge gets one to four timeouts within a span of twenty seconds when i run ping -t to check on it.

What I did to troubleshoot:

  • bought a second hue bridge. same behaviour.
  • changed lan cable from bridge > omnia, no improvement
  • changed lan port on the omnia, no improvement
  • ran ping -t on all other devices connected to the omnia (RasPi, NAS) no timeouts!
  • connected the hue bridge dirctly to my main router = no timeouts

That led me to the following conclusions:

  • the WiFi link and relayd configuration works
  • the bridge works connected to the other router, too
  • is has to be something specific to the omnia AND the bridge, but I´m not able to narrow it down.
    Is the omnia refusing packets ? actively blocking the hue bridge? if so, why?

Any hints on what to check / do? (besides installing a lan cable to that room where the omnia is…)

Thanks!