Why won't one of my gas stove's burners ignite?
How many clicks, sparks, does it usually take to ignite? If you have gas on, and try to ignite another burner, it will ignite. You have sparks when you try to ignite this one by itself? If so, then the igniter is good, unless it normally sparks longer, then it could be faulty. However, you probably have a faulty gas valve. It is not opening the gas for ignition.

What is the stove model number? Can you post a video of the problem?