Hello, i just noticed that only the RSSI_TYPE parameter is found in mission planner when searching parameters.
I am using ArduCopter V3.6.3 (tried with ChibiOS and without) and MissionPlanner 1.3.62.
The board is Pixhawk 2.
Btw, happy holidays! 
happy holidays to you too!
specific RSSI parameters are collapsed as long as TYPE is set to 0 = disabled.
you need to set RSSI_TYPE to your desired value other than 0, write and reload parameters to un-collapse specific settings.
cheers, basti.
That worked, thanks a lot. And a happy new year 