Ray Jenkins wrote:

The other three work properly: First you hear a clicking, sparking noise,
and the gas lights.

But this clicking, sparking sound does occur on the faulty one.

We had that problem in a relatively new stove, and after reading
something somewhere, I decided to try cleaning it well. I stuck the
parts that the flame goes around in a baggie with a half-cup of ammonia
and left it for a day or two (nontoxic oven cleaner method), then after
the fumes had a good chance to "steam" everything off, I scrubbed well,
dried, and replaced on burner.

It worked like a charm. This might work for you also, and I sincerely
hope it does.

--
I know God will not give me anything I can't handle.
I just wish that He didn't trust me so much. - Mother Teresa