It sounds like your hot rod (igniter) is not getting hot enough to fully ignite the pellets. To troubleshoot, I suggest you do the following.
1. Open your grill lid and remove everything: grates, drip pan and flame shield..
2. Remove any pellets in the fire pot.
3. Check to see that the hot rod is extending approximately 1/4" into the fire pot. If it is noticeably more or less than 1/4", adjust the hot rod.
4. With the grates, drip pan and flame shield removed, prime the auger to place a small quantity of pellets in the fire pot.
5. Now with the lid open so you can observe, set the controller temp to about 225F and then attempt to ignite the grill.
6. You should see the hot rod getting red hot. You should hear the fan start to blow air into the fire pot. You should hear the auger turn and push more pellets into the fire pot.
7. Soon, you should start to see the pellets start to smolder putting out a thick white smoke.
8. A few minutes later, the pellets in the fire pot should be fully burning and the hot rod will turn off. At this point, you should see thin blue smoke. From this point onward, combustion should be self-sustaining.
9. Close the lid and allow the grill to come up to temperature (225F). Then initiate the shutdown sequence to burn off excess pellets in the fire pot.
If you were successful, replace the flame shield, drip tray and grates.
I always start my Ironwood by priming the auger, setting the controller to 225F and then igniting the grill with the lid open until I start to see thin, blue smoke. If I want to cook at a higher temperature, I move the controller setpoint up 50F at a time until the desired setpoint is reached. If you try to jump the setpoint too much, the auger can feed pellets into the firepot too rapidly and smother the fire. Adjusting the temperature setpoint in increments allows the controller to adjust the pellets and air more smoothly.
Please try the troubleshooting procedure and then post your observations so others might be able to help. If things work successfully, then you will be back in business.