Gas Cooktop Ignition Problem

Regarding My 12 Yr Old Maytag MGC5430BDQ, 30", 4 Burner, Natural Gas Cooktop.
This Week (12-7-17) I Replaced All 4 Ignitors With New Factory Parts.
Two Of The Burners Will Not Auto Ignite When The Dial Is Turned To The "lite" Position.
The Ignitors Are Actively Ticking/Sparking and Gas Is Being Fed Into The Burner Head.
I Know The Gas Is There - Because - With The Dials Set To "lite", If I Put A Lighted Match To The Burner Head Both Will Instantly Light, And Work Perfectly At Any Temp Setting.
FYI The Two Burners Are Left Rear 5,000 Btu And Right Front 12,500 Btu.
Am Baffled. Please Help. Thank You.