One thing that will cause problems is bad ground(s)
Check, clean/tighten ground connections for gas valve.....
Clean/tighten the spark electrode ground. From the picture it appears that the grounding for spark electrode is via the mounting bracket....remove spark electrode assembly and clean up the bracket and bracket to frame location/screws
Spark electrode to ground rod gap should be 1/8" and electrode needs to be positioned directly in flame
Thought on Suburban the 'light' came on then went off when flame was established and then would come back on if a fault occurred.