anybody with the f600k has the same issue? i dont remember if i was not able to connect out of the box..but lately i just noticed it now... anybody experienced the same thing? if yes what was your work around 
i believe a wifi ssid should be the same regardless if you set it to 5GHz or 2.4GHz. i use a MyFi which i could set to 5GHz or 2.4GHz..my previous G3 can cpnnect to my MyFi on 5GHz...but looks like my F600K does not.. hardware isse? *sobCheck your routers settings, is the password the same for that band? Notice the ssid is different? Try manually adding the SSID to the phone. Also the 5ghz band doesn't cast as far, try being closer to the router.
sent with Hugz from my new fully stock, non-rooted VZW LG V10 VS990 which an old faithful still working Rezound helped me to afford to get
I have Belkin router which runs both 2.4 + 5Ghz simulantanously.i believe a wifi ssid should be the same regardless if you set it to 5GHz or 2.4GHz. i use a MyFi which i could set to 5GHz or 2.4GHz..my previous G3 can cpnnect to my MyFi on 5GHz...but looks like my F600K does not.. hardware isse? *sob