Igniter sparking backwards, Kenmore 665.72022100 Oven

[ttsmith]

My Kenmore gas oven (665.72022100) started getting sluggish to ignite: the gas would turn on, I'd hear the clicking of the igniter, but maybe half the time it would fail to light. I cleaned the igniter a bit and that helped slightly but not enough so I just figured I'd get a new igniter.

After installing a brand new igniter the oven fails to light frequently still, perhaps even more so now. I did what I should have much earlier: took the bottom covers out and watched as it tried to light. I can see easily what the issue is but I'm not sure the root cause or how to fix it. With most of the igniter sparks the spark is not jumping from the tip to the cage as intended, but sparking off the back of the igniter instead. This is an L style igniter and I believe it's arcing between the corner of the L and the gas tube but I can't be certain of that.

I've attached a photo of the style igniter I have, and have an arrow to indicate where I think it's arcing from. There's a porcelain sleeve that covers the corner gap between the two lines of porcelain insulation. Maybe that isn't enough insulation in this case? But it's strange to me because this is how it's designed, and a brand new igniter. 

Any ideas how to resolve this?