Hi,
I have a similar issue with a Lamona Gas Hob (HJA 1140). The igniter button had jammed solid, so to be certain of success I’ve bought new igniter coil with electrodes from UK Whitegoods and fitted it exactly as the original came off, tested and No Spark anywhere !
This replacement is identical in every way and recommended for this HJA model.
I’ve fixed the press button on the old igniter and re-fitted that with its original electrodes, and its sparked, bit only on some burners, and amazingly it soon ‘died’ ! I can hear it sparking inside the unit, but no spark at any electrode.
Any suggestions?