KyNola nailed it (as per usual)! Once the grill reaches 160, the temperature is controlled by the fan speed and auger turn rate, so unless there's something causing the grill to drop below 160 (such as an over-full firepot, where the pellets can't maintain a good fire), the igniter won't turn on again during a cook. So if the Pellet Boss IS saying "Igniting" after that amount of time, there's something interfering.
The little "A" on the screen shows when the auger is turning, which will happen off and on no matter what temperatures you're cooking at (it would stay on constantly if you're cooking on HIGH).
Cleaning the thermocouple is always a good idea to do every few cooks anyway, just to make sure it's clean and registering temperatures without interference. Making sure all the vents and grease chute are clear and don't have grease clogged in them will make sure the air-flow is allowing the grill to function as it should as well.
Keep us posted-- we'd be happy to troubleshoot some more if those things don't alleviate the issue! (
support@makgrills.com or 503-623-1234)
-Kat