@Michal-Mormon
S_SCENE_CONTROLLER can send messages V_SCENE_ON and V_SCENE_OFF. If you send those messages for the first time, domoticz will create new switch with the name 'scene'.

@ErrK I had similar problem with my hc-sr501 pir. It seems that some pirs are very sensitive to any electromagnetic noise. For me pir was reporting false positives each time nrf was sending data. You can easily test it: just remove any gw.send commands and solder led to pir output (of course through 1k resistor). When pir is detecting a motion output goes high so led will go on for the time set by pir potentiometer. In my case each sending (when for example battery level was reported each 30 min) resulted in false pir trigger.
It seems that this depends on specific device. I switched pirs between my sensors and this false triggering went to other node :-)
Finally I solved this problem in software. I can share my sketch that is working well for two of my nodes.

Btw: there are many discussions on the web about those pir false triggering concerning remote radio nodes. I took the idea of software solution from there.

Of course in your case reasons can be different...

@Michal-Mormon
Yes, exactly! It looks like without scene_off sent from scene controller in domoticz it will be one-time action (since if this scene switch is switched on you cannot switch it on again). You can try to setup automatic switching it off in domoticz.