Wa8yxm. Op here. Thank you for your post, I am not knowledgeable in this lp stuff and your explanation helped me a lot. I am leaning towards the stay a while check valve is the culprit. I am a fulltimer, the stay a while is 7 yrs old. I have a call into the local mobile tech to come and check the entire system.
Your post mentions pressure, length of hose all leading to a long time burn off. When I closed the aux tank valve I let the stove burners go for 15 minutes. The burner flame never went out or even lessened. Should I try it again and allow even more time?
Thanks again all. And of course a cold front is on the way :)