I have a Whirlpool gas oven Super Capacity 465.
The four cook-top burners work ok.
When I turn on the oven on broil, I hear gas hissing and igniters ticking. Within a second it ignites the top burner inside the oven. I could see flames from the jets.
On the other hand if I use the bake setting (to use the lower burner). I hear gas hissing, igniter ticking but it doesn't light up. It stops for a minute or so and tries again. It does light up rarely sporadically but not dependable. I opened the bottom panel to expose the burner and sprayed some oven cleaner over the jets. No luck. If I manually ignite the lower burner, it ignites. To try this I lighted up a small piece of paper, close the oven door and turn on the oven on bake setting. When the lower burner is burning, I can see all jets have a flame. I did this only to diagnose and later closed the bottom panel.
I have used the self cleaning feature of the oven a few times already without any luck.
My issue is similar to this but in my case the igniter is firing.
Some time back I discovered a gas leak from behind the oven but it was fixed by the gas company. They unscrewed the gas inlet hose and applied some kind of grease and tightened it again. I'm not sure if this could be related.