This might be of help to some, i recently purchased a GMG Daniel Boone and tried for a few weeks without success to update the firmware on a home Wi Fi broadband internet connection as i dont get cable or ADSL internet , well i finally had some success which i hope may help someone
Firstly i had a new work provided home Wi Fi Huawei 4G internet connection but no matter what i did i couldnt update the firmware on the gMG. I tried it all and it wouldnt update no matter what i did or where i placed routers or Iphone 6, i got FAL everytime
I was lucky as i had an older Telstra Wi Fi Hub running 3G that hadnt been binned by work yet. It had the Wap2 password, no spaces in the name, anyway:
A; Again i tried to update it and first time i got Fail again even though my iphone 6 was within 20 feet. Almost ready to give up i placed the iphone and router basically right on top of the hopper and success, it updated finally after 4 weeks of trying.
So from my experience it works with 3G not 4G and the Iphone 6 and router has to be almost within a few feet of the grill, so im up and updated to firmware 5.8 and happy days as it also reads temps in F not C which is a great bonus
Also have built some upper grates to fit which went well with the jerky, enjoying the GMG so far, have done the usual briskett, a couple of pork butts, a bunch of cape Grim beef ribs, pizza, urban grillers Duck, jerky and now some jalapenoes for chipotles, enjoying the grill
Cheers
Mike