Hi,
I´m running domovea in parallel to openHAB and do not face issues.
- Maybe it help to configure the local IP address for the binding (parameter “localIp”
- Try using “TUNNEL” instead of “ROUTER”, this works for me.
I had some trouble there.
On the other hand: Maybe your IP-Interface is not configured or capable to allow multiple connections.
A quick look into the manual should enlighten you here 
I switched from using the hardware IP Interface to knxd on a PI, this was more stable (and actually cheaper) than the Weinzierl interface I have installed.I´m using the busware Pigator, details on setup can be found here .
Kind Regards,
Thomas