If the orifice is clogged, the flame will be smaller, and probably
wouldn't light in the first place. *The OP has not said what happens
if he tries to light it using a match, the first step in *diagnosing
his problem.. *But if the air supply that goes aound the orifice has
dirt or debris in it, like maybe spider webs,, insufficient air will
flow and that will cause flame-out also.

Hi. I'm the OP. If I light with a match, it'll go out on its own in
a few seconds.