Hue Emulation can't turn on lights but can turn them off!

Hi everyone,

first of all: I’m a newbie when it comes to openHAB.
I have setup the Hue emulation in openHAB 3.3.0 within docker. I added a Shelly device as Item and have two other Hue clients which can see the emulated Hue bridge and the Items.

Now problem is: I can’t turn the emulated lightbulb on:

When I turn on the Item in openHAB, and turn it off with one of the Hue-Clients (Logitech Harmony ode Busch-Jaeger free@home) it works. When I try to turn them on, it won’t.
I tried to debug the problem and found:
When I send ‘{“on”: true}’ to the Hue emulation URL via curl

# curl -X PUT -d '{"on": true}' http://192.168.0.1/api/testuser/lights/6/state
[{"success":{"/lights/6/state/on":true}}]

it works, but if I send value Hue-API-JSON with another parameter:

# curl -X PUT -d '{"bri": 254, "on": true, "ct": 500}' http://192.168.0.1/api/testuser/lights/6/state                                                                                                                               
[{"success":{"/lights/6/state/bri":254}},{"success":{}},{"success":{"/lights/6/state/ct":500}},{"success":{"/lights/6/state/on":true}},{"success":{"/lights/6/state/sat":0}}]

so both of my clients are sending more than "on": true and that won’t turn on the device.

In the log, if anything else as only {"on": true} is send, the command is intrepretetd as 100:

14:24:25.414 [INFO ] [openhab.event.ItemCommandEvent       ] - Item 'Testlampe_Betrieb' received command ON
14:24:25.415 [INFO ] [openhab.event.ItemStatePredictedEvent] - Item 'Testlampe_Betrieb' predicted to become ON
14:24:25.418 [INFO ] [openhab.event.ItemStateChangedEvent  ] - Item 'Testlampe_Betrieb' changed from OFF to ON
14:24:26.221 [INFO ] [openhab.event.ItemCommandEvent       ] - Item 'Testlampe_Betrieb' received command OFF
14:24:26.223 [INFO ] [openhab.event.ItemStatePredictedEvent] - Item 'Testlampe_Betrieb' predicted to become OFF
14:24:26.224 [INFO ] [openhab.event.ItemStateChangedEvent  ] - Item 'Testlampe_Betrieb' changed from ON to OFF
14:34:12.310 [INFO ] [openhab.event.ItemCommandEvent       ] - Item 'Testlampe_Betrieb' received command 100

Could anybody explain what’s wrong or how I could debug this?

kind regards

datenpirat