Genesis II LX 640 Not Lighting

Hey all, long-time lurker, first-time poster hoping to get some advice. A work client gifted me his old Genesis II LX 640, and it needed some love. I’ve replaced a bunch of parts, but I’m still having an issue.

I’m getting gas to the main burner tubes but no flame. I can smell gas, and when I run a match over a burner, I can hear it trying to light, but it won’t take. The side burner lights normally with the knob, no match needed.

The burner tubes are one of the few things that I didn’t replace with genuine Weber parts, and they’re shaped differently from the OEM tubes. I went ahead and ordered a Weber set just to see if that fixes the issue, but I wanted to ask if there might be something else going on. I’ve checked the gas lines for leaks and didn’t find any.

Here’s a list of the parts I’ve replaced:

• Gas line to side burner
• Gas line to main burners
• Gas regulator
• Igniter kit (module, electrodes, wiring, etc.)
• Burner tubes
• Bunch of miscellaneous parts/accessories (grates, flavorizer bars, grease tray, knobs, etc.)

Appreciate any suggestions!