Last year I picked up a Blue Rhino portable gas grill from Lowes for $5 that was on clearance becaues it was missing the regulator with control knob that fits the 1lb tanks. I put a lever style gas valve on the burner venturi tube to control the flame and hooked a 25' propane hose to it with a QD plug on the other end to fit the gas coupler on the trailer. Works like a champ and the 25' hose gets me plenty far away from the trailer and onto a nearby picnic table.
As others have stated you were double regulating your propane. Too much regulation is never a good thing, if you know what I mean.
2006 23B Hybrid with 10k round bar WDH
2011 F150 4x4 SCREW Ecoboost, Max Tow, Integrated TBC, 3.73 LS axle, Firestone Ride Rite airbags.