There are several posibilities.. One is good news, the rest not so much.
Good news first: Propane is odorless. so they add a chemical to the tank so you can smell it,, NOW,, Normally this chemical is destroyed by the flame in a properly operating burner HOWEVER... If the burner is in need of ROUTINE MAINTENANCE or if the tank is near empty of if over time the concentration of the chemical has increased .. You might smell it.
Now the bad news:
And if the lines are leaking you should smell it.
Suggestion: If you are not comfortable working on propane systems have a professional check it out.
BUT FIRST: I have fixed ONE "I smell propane" problem for a fellow RVer,,, And by the way, when it comes to propane systems this is the only FIX I am willing to do on YOUR system.. I am very comfortable working on mine.. But on yours this is the limit.
I took a look at her stove... The knobs said OFF OFF LOW OFF.
I'll bet you can guess how I fixed it.
Check that one first.
Home is where I park it!