Challenge with KNX binding, “response timeout waiting for confirmation”

Hallo,
I do have a big challenge with the KNX binding. I have read a lot of topics and tried multiple things but I can’t get it work properly. I personally use the KNX PROServ as KNX IP connection. There I can only use the tunnel connection. Following settings I have made:

autoReconnectPeriod = 10
busaddr = 1.1.231
ignorelocalevents = true
ip = 192.168.178.3
localIp = 192.168.178.110
port = 3671
service.pid = org.openhab.knx
type = TUNNEL

the unit and the settings worked perfect with openhab 1 but I have a challenge with openhab 2. And no I will not buy a ip connection with router function. The KARAF shows the binding version 1.9.0. this is a released version not a snapshoot.
If the system reboots it reports successfully connection with the KNX network. but whenever I send something to the KNx bus it works but very slow and pulses the request multiple times I can see this in ETS4 when I log the commands.

When I log the Openhab binding is see following Error for each command:

23:43:06.189 [ERROR] [.binding.knx.internal.bus.KNXBinding] - Value ‘21.6’ could not be sent to the KNX bus using datapoint ‘command DP 2/1/5 Temp_GF_Kind, DPT main 0 id 9.001, low priority’ - giving up after second try: no confirmation reply received for L-Data.req from 1.1.231 to 2/1/5, low priority hop count 6 repeat tpdu 00 80 0c 38
23:43:06.194 [INFO ] [marthome.event.ItemStateChangedEvent] - Temp_GF_Kind changed from 21.8 to 21.6
23:43:06.189 [WARN ] [tuwien.auto.calimero ] - KNXnet/IP Tunneling 192.168.178.3:3671: response timeout waiting for confirmation
tuwien.auto.calimero.exception.KNXTimeoutException: no confirmation reply received for L-Data.req from 1.1.231 to 2/1/5, low priority hop count 6 repeat tpdu 00 80 0c 38
at tuwien.auto.calimero.knxnetip.ClientConnection.doExtraBlockingModes(ClientConnection.java:236)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.knxnetip.ConnectionBase.send(ConnectionBase.java:269)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.knxnetip.KNXnetIPTunnel.send(KNXnetIPTunnel.java:149)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.link.KNXNetworkLinkIP.onSend(KNXNetworkLinkIP.java:263)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.link.AbstractLink.send(AbstractLink.java:304)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.link.KNXNetworkLinkIP.sendRequestWait(KNXNetworkLinkIP.java:240)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.process.ProcessCommunicatorImpl.write(ProcessCommunicatorImpl.java:466)[209:org.openhab.binding.knx:1.9.0]
at tuwien.auto.calimero.process.ProcessCommunicatorImpl.write(ProcessCommunicatorImpl.java:438)[209:org.openhab.binding.knx:1.9.0]
at org.openhab.binding.knx.internal.bus.KNXBinding.writeToKNX(KNXBinding.java:158)[209:org.openhab.binding.knx:1.9.0]
at org.openhab.binding.knx.internal.bus.KNXBinding.internalReceiveUpdate(KNXBinding.java:126)[209:org.openhab.binding.knx:1.9.0]
at org.openhab.core.binding.AbstractBinding.receiveUpdate(AbstractBinding.java:119)[176:org.openhab.core.compat1x:2.0.0]
at org.openhab.core.events.AbstractEventSubscriber.handleEvent(AbstractEventSubscriber.java:38)[176:org.openhab.core.compat1x:2.0.0]
at org.apache.felix.eventadmin.impl.handler.EventHandlerProxy.sendEvent(EventHandlerProxy.java:415)[6:org.apache.karaf.services.eventadmin:4.0.8]
at org.apache.felix.eventadmin.impl.tasks.HandlerTask.run(HandlerTask.java:90)[6:org.apache.karaf.services.eventadmin:4.0.8]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_65]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_65]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)[:1.8.0_65]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)[:1.8.0_65]
at java.lang.Thread.run(Thread.java:745)[:1.8.0_65]
23:43:19.975 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Received groupWrite Event.
23:43:19.978 [INFO ] [smarthome.event.ItemCommandEvent ] - Item ‘Temp_GF_Kind’ received command 21.7
23:43:19.985 [INFO ] [marthome.event.ItemStateChangedEvent] - Temp_GF_Kind changed from 21.6 to 21.7

I have read multiple reposts already and tried a lot things but it does not help. Has anyone a idea what it could be? As you can see finally I receive room temperature so it works basically.

Any help is highly appreciated.

Thanks in advance.

Marcel