Is anyone seeing issues running at higher temps since the latest firmware upgrade?

I have the 850 since last May. It's been pretty solid. I cooked all levels of temps though the Chicago winter. No problem.

Since the latest firmware upgrade, I have noticed some strange behavior.  On a chicken cook I set it to 450 and the grill was only hitting 350. Chicken came out great and in the normal cooking time, but left me wondering. I had not cleaned the grill and had some old pellets.

Today I attempted a reverse sear on some prime ribeyes. Cleaned grill, fresh pellets. 224 for 45 minutes no problem. Put the aluminum grill grates in and set it to 500. 30 minutes later it's only at 350. Went ahead and finished the steak anyway due to time constraints. Pulled the food, ate dinner and went back out. Now the grill humming at 450 and climbing.

My two thoughts:

1. I'm a software programmer, so the upgrade screwed something up. Like the auger speed when getting up to set temp. Only thing I can think of that changed was firmware upgrade.

2. I also notice this when I load up the two or three grates which I did in the last two cooks. Could it be an airflow problem or the food causing the temp hard to recover due to a heat sink effect?

Wanted to hear if anyone else is seeing the same thing recently.

Thanks!

Thanks for the good advice!  I will do that and see if it helps.

I don't know how the 850 is set up, but on my older Traegers, when the heat does not seem to register correct, I have to clean the temp probe.

I sort of learned that the hard way.  I make it a habit of cleaning the RTD probes at the start of each cook.

Update. I did not get to clean the probe. It's not exposed and did not feel like getting access. Cooked a chicken and baked potatoes yesterday at 450 and it does stuggle a bit when the food first goes on and is cold. I have been very happy with the results. Overall very good into 350 range and slower recovery times up above 425. No big deal.

For reverse sear, I think I will fire up the weber kettle for the sear next time. See how that goes.

Overall, still very happy with the 850 one year into it. Cooked on at least once a week all through Northern Ill winter.