Found a work around. Instead of configuring the things in PaperUI, I configure the MQTT Gateway and the sensor through the openHab things file. I followed the example that @dakipro wrote in the openHab controller main Web page (https://www.mysensors.org/controller/openhab). Thanks @dakipro.

Hi,

I have a MQTT Gateway, 1 sensor, 2 things, one for the temperature and the other for the humidity.

Node is is 105 and child 0 and 1.

2 items are configured, everything is working well.

But when I restart the Raspberry PI, the status for the 2 things is UNINITIALIZED - BRIDGE_UNINITIALIZED. In the openHab log viewer I see
Node 105 found in gateway
Child 0 not present in node 105
Child 1 not present in node 105.

To fix the issue, I delete the 2 things and create them again with node 105 child 0 and 1
After that no more issue.

I don't want to delete the 2 things every time I reboot the PI.

Any suggestions

Thanks