Gas cooktop phantom starter

I have a Thermador SGC365RW 5-burner gas cooktop. Whenever I light Burner 1, the starter for burner 4 repeatedly sparks. This lasts as long as the gas is turned on for Burner 1. It's not reciprocal: i.e., when I start 4 there is no spark on 1. No damage done, but it's annoying and shouldn't happen.



Is it fair to assume that something is arcing inside the box? Or, do I just replace the starter on 4?



Don't know much about how these things work.



Any help is appreciated.

Gas cooktop phantom starter