Yes the water heater was working before and is now experiencing fire blow back. The blow back melted the fuse it had before and I had to find a new one. Now I I don't put the new one on cause worry of it melting again. Regardless of me moving back and forth the air vent tube it will not adjust the flame and it stays the same amount of flame fully closed or fully open. As for the pressure in the line it was working when I first moved into the trailer about 5 months ago. I barely open the propane tank and its been sufficient amount of pressure for the flame, and now there's flame kick back and I don't know why. Thank yall for your responses its much appreciated.
And thank you kirk 🙏 for the warm welcome