We normally use a big propane tank at camp, where it didn't work at all.
I am using a small 1 lb canister to test it after cleaning here at home. After cleaning, the pilot light/thermocoupler works fine, and lit up... that's when I noticed the issue with the large flame.
There is no corrosion on any of the tubes; everything looks new on the inside. I don't think it's a leak, because the one ceramic plate works fine. The other one is casting a big flame and not glowing.
It's never been "disassembled", just covers, etc removed to allow cleaning. And I think this cleaning is the first one we've done.
We have a good working one at camp; I'd like to use this one in our treestand Monday for the first day of rifle deer season.