slight gas odor

I have an Amana range ARGS7650WW (propane)

Recently, we’ve noticed an ever so slight gas odor coming from it when it is not being used. I think I’ve narrowed it down to coming from one of the valves. (sniff test).

I guess I’m wondering if anyone else has had this issue. I assume I will need to replace the valve but I’d like to know if it is the likely problem. I’ve sprayed LeakCheck all over it but don’t see any bubbles, but the stem that the knob goes onto (where I’m smelling the gas) protrudes out through plastic so it’s difficult to get the spray in there.
Has anyone else had this problem?

Thanks!