OnCourse Software

Dear Dave
I am quite new to PF3. Have it running under P3D 5.3. CP Mode 2, auto tune to inital facility.
When departing from Vienna LOWW everthing works as it should.
But when departing from a smaller airport like Salzburg LOWS, Innsbruck LOWI or Klagenfurt LOWK I face a problem:
Initial contact is made and I get "Report ready for push and start" but when pushing hotkey 0 (have altered it to O), I can hear the hotkey tone but nothing is happening. So I am stuck.
noticed that all these airports have only a frequency for Tower and no ground or delivery. I think that's the problem.
Tried to generate some fake frequencies for LOWI for ground and delivery but did not help.

So what I am doing wrong?

regards Manfred from LOWW