Viking oven ignition troubles

Hello,

I am having trouble with a viking range I recently bought and converted to propane. Surface burners and griddle work fine.

30" Oven burner lights immediately, the igniter keeps firing, and then the gas valve closes after about 10 seconds shutting down the burn. Re-tries ignition after about 30 seconds, same thing.

Same thing happens with the broiler burner.

18" Oven does not work at all.

Checked resistance on all the gas valves, all were <3ohms.

Swapped ignitors between the 2 ovens, no change.

Any thoughts on what’s going on?