Overbridge does only work for two synths simultaneously

Hi together,
I have a problem with my overbridge setup. Maybe anyone can help me.
When I have Rytm und Analog Four both turned on, then I can hear only the sound of one of them. (And in the Overbridge Control Panel there is also nothing to see on the meters.) But both machines have a green light in the Overbridge Control Panel.
When I turn off the machine which was doing well, the sound of the other machine suddenly appears and also the the meters in the Overbridge Control Panel start to work as expected.
And it is exactly the same when the other machine works fine and I turn it off.

My Setup is:

  • MacBook Pro with OS10.12
  • Ableton Live 9
  • Overbridge 1.15
  • Analog Rytm 1.31B
  • Analog Four 1.24C
  • Overhub

Hope anyone has a solution to this, because at the moment I can use only one machine with overbridge in my setup.
Thanks a lot.

Flo