Item state of new item never changes with OH2.4 and KNX binding

Hello,

I can not get on with my setup, maybe someone can see what I’m unable to see at the moment?

I had a working KNX setup before, the only thing I changed is I added a new KNX device to the bus. After that I changed the .things and .items files accordingly. I activated trace output and the KNX messages are received, but the item state is never updated. I’m guessing it’s something very simple, but I just can’t find it.

things file:

    Thing device gf_stairwell_frontdoor [
    address="1.1.113",
    fetch=false,
    pingInterval=300,
    readInterval=3600
] {
    Type contact       : gfStairwellFrontdoorOpened                       [ ga="1.001:5/3/3" ]
    Type contact       : gfStairwellFrontdoorLocked                       [ ga="1.001:5/3/4" ]
}

items file:

Contact  gfStairwellFrontdoorOpened         "Haustür geöffnet [%d]"                                     { channel="knx:device:bridge:gf_stairwell_frontdoor:gfStairwellFrontdoorOpened" }
Contact  gfStairwellFrontdoorLocked         "Haustür verriegelt [%d]"                                   { channel="knx:device:bridge:gf_stairwell_frontdoor:gfStairwellFrontdoorLocked" }

log:

2019-07-02 14:34:05.354 [TRACE] [nx.internal.client.AbstractKNXClient] - Received a Group Write telegram from '1.1.113' to '5/3/4' with value '[0]'
2019-07-02 14:34:05.356 [DEBUG] [.internal.handler.DeviceThingHandler] - onGroupWrite Thing 'knx:device:bridge:gf_stairwell_frontdoor' received a GroupValueWrite telegram from '1.1.113' for destination '5/3/4'
2019-07-02 14:34:05.358 [TRACE] [.internal.handler.DeviceThingHandler] - onGroupWrite Thing 'knx:device:bridge:gf_stairwell_frontdoor' processes a GroupValueWrite telegram for destination '5/3/4' for channel 'knx:device:bridge:gf_stairwell_frontdoor:gfStairwellFrontdoorLocked'
2019-07-02 14:34:05.361 [TRACE] [g.knx.internal.dpt.KNXCoreTypeMapper] - toType datapoint DPT = 1.001