Blender 3.1 Delete Light groups

I created a light group for side lights “Side_LightGroup” and now I wanted to separate those light into “Side1_LightGroup” and “Side2_LightGroup” but I can’t, seems that if I start a Light group with “Side” blender will assume “Side1_LightGroup” .

Another question, how do I delete a non used LightGroup?

Thanks

Hum, I’m not sure what you’re doing exactly.

You should manage light groups from here :

And then assign lights objects here :
image

Looks like in the second panel you can enter names that don’t exist for convenience , but it won’t create a lightgroup, at least in my blender version.