I went through this process FIVE times and the app is still stuck!! ?
Sorry for the frustration, I have spoken to Traeger support many times without issue. I was a field engineer for many years, patience and kindness go a long way.
I just replaced my controller today. It had a wonky control dial, it made manual temp adjusting a pain.
Here's what I did;
1- opened the iPhone app and removed the old grill.
2- deleted the app and data.
3- re-installed I app and signed into my Traeger account.
4- went to phone settings and set my wifi to connect to my home's 2.4ghz network.
5-Replaced the controller in the grill, and placed the new QR Code sticker inside the pellet lid, over the old one.
6- powered up the grill.
7- opened the app and selected "add grill"
8- it verified that I was on my home network, had me enter network password.
9- it then asked have me scan the QR Code sticker, then connected to the controller's network (Trager-xxxx).
10- it then connected directly to the grill and passed my wifi network info to the controller which then connected to my home network.
11- it then downloaded files, rebooted, and connected to my home network.
12- the app verified the wifi connection and led me to name the grill, completing the install.
My Firmware is now 02.00.01, the old one I just pulled out was 02.00.02 but they aren't updating any higher right now.
From experience, sometimes you have to do this more than once.
Also, while I was swapping out the controller, I noticed that the grill Temp sensor is a K Type thermocouple. That's a good quality, high temp capable setup!