Two details strike me here, one is the possibility that there are two regulators in the line between the large tank and the burner, the other is that the hose is too small for its length.
Two regulators would result it very little to no gas flow. Too small a hose for the length would also result in low pressure at the burner.
It is also possible, that the little campfire deals with the high-pressure/low-pressure issue by simply having a pinhole through which the high pressure propane has to squirt in order to restrict flow low enough for the burner, which is actually a low pressure device. If this is so, it must be connected to a high pressure line.
