I don't know what to tell you.
Does it continue to come out after a few (
seconds? Or is it just a puff at the beginning?
The type of gas hose you are using has to be labeled as "type T" when using propane.
The hoses used with acetylene will disintegrate from the inside when they get used with propane for very long and that can get dangerous.
You usually get a gummy liquid spitting out of the torch when that happens.
Wish I better information for you.
This the first I have heard of this.