Older Bluestar Range LP gas, Model RPB366BSS

Standard 6- burner BlueStar range w/IR broiler. Oven ignites & works fine, but top Broiler stopped working. Replaced Gas safety valve a year or two ago, so its like new. (3.3-3.6 Amp version). Installed new broiler igniter (pulling 3.5 Amps) @ the valve, & gas safety valve has continuity on both top & bottom valves. Also top (broiler valve is 1.0 OHM, and bottom (Oven valve is .9 OHM, so within spec) . Also installed a complete new control/knob thermostat last week (problem happened before this)

This is an analog stove, with not many electronics. When knob is turned to Broil, the broiler igniter glows bright orange and pulls 3.5 Amps at the valve, but broiler just won't ignite. Faint whiff of gas can be smelled when igniter is glowing. Igniter is properly mounted in the four, pre-drilled factory mounting holes, so I don't think its a proximity issue, as the broiler always lit up fine.. Also tried two or three igniters, that all checked out OK, (3.4-3.6 Amps) Really stumped since all the electronics seem to be checking out. What tests would be done next? Do IR broiler elements go bad? Last time it worked, I remember it being weak and not as hot as it used to be. Any help would be appreciated.