Adding a light switch rfxtrx. entity_id changes

I’ve been trying to add a Nexa LWST-615 light switch. It pops up in HA every time i press it, but it changes the entity_id every time I restart HA. How can I give it a name and use it when I can’t add it properly?

This is from RFXmngr:

Packettype = Lighting2
subtype = AC
Sequence nbr = 28
ID = 1481FFA decimal:21503994
Unit = 11
Command = On
Signal level = 8 -56dBm

Add the device id to the configuration as described here https://home-assistant.io/components/switch.rfxtrx/

I had to add another swith to devices first and then it worked. I’ve tried this over and over without success… Thanks for fast reply though!