I will add my name to this list. I have tried two networks, 2.4ghz only and tried the Mesh. Spoke with Traeger support, Verizon support and Eero support multiple times. Deleting app, Different phones. iPhone and iPad hotspots, routers within a few feet, phone in airplane mode, and farther from grill.. Faceplate facing router. Changed names of networks and passwords. I have tried every solution I have come across. And open for more. Nothing works for me. (I did have it work once for a short time, but now it won't find that network again) They tell me to be patient. 3-months and I'm becoming less of a fan of Traeger.
A couple notes from another post are below that may help. I finally got mine to connect today after I installed a new controller and did #1 and #2 below during the install process. Good luck!
Yes, we ran though the whole setup process a number of times.
Made sure phone app (droid) was 1.4.1 .
Made sure firmware was 3.0.0 (for Timberline only, otherwise 2.0.0).
Made sure phone WIFI was using 2.4 GHz channel from router.
Uninstalling the app on my phone. Cleared cache for traeger app on phone.
Shutting down / Restarting the grill.
Turned off 5GHz wifi channel on router, keeping the 2.4GHz channel running.
Changed WIFI pw to exclude special characters.
3/11/20 Update: New controller arrived so I installed it today. Initially tried to connect, same result as before"Unable to join network" message on phone. I did a couple other things that we didn't try before and WAS able to connect to WIFIRE !!
1.) Make sure the grill menu displays the WIFI settings when trying to connect. Previously I wrote them down on paper and I'm not 100% sure my grill menu displayed WIFI settings when I tried to connect.
2.) Brought my phone right next to the grill when setting up the connection. I'm not sure how this made a difference but it seemed to. My WIFI router is high end and I can get a signal 300 ft beyond my yard, but regardless having the phone right next to the grill seemed to help.
3.) My WIFI pw includes special characters and is longer than 8 characters and my second router channel running 5 GHz was also running, so these 2 variables did not seem to impact my ability to connect.
Good luck with WIFIRE.