Robb - like you, I always clean out the firepot between cooks regardless of how long or hot, so that is not a factor. I live in San Clemente, CA - it may have gotten down to 60 overnight lately, but it has been in the low to mid 70's lately during the day, as during this sear attempt. I used CookinPellets' wine barrel oak that had maybe 25% alder in it (a camp chef bag I'm trying to use up). No, I did not prime the firepot, but really ignition with the MAK is pretty quick from "scratch". Yes, I have the newest FZ and I use MAK's grill grates.
I'll try some 100% Oak I have next time. I thought it might be the pellets, so I guess I need to try that before calling the MAK gang about it.