JSON sensor problem SITL/ros_gz for custom model

Hi everyone,
I’m trying to set up a simulation with the ardupilot ros_gz_ bridge and my own model.
Running everything with an example (eg ros2 launch ardupilot_gz_bringup wildthumper_playpen.launch.py) works just fine, but running with my own model, no data is sent.
I just get the following warnings:
[dds_udp.parm --synthetic-clock -4] No JSON sensor message received, resending servos
[ruby $(which gz) sim-1] [Wrn] [ArduPilotPlugin.cc:1589] Duplicate input frame

Can anyone help me with this?

I attached both my model and the ros2 launch log
my_model.txt (38.9 KB)
launch-log.log (18.5 KB)