Question: Can't connect to 5GHz Wifi
I'm using Iphone 6 plus, 128G but after upgrading to IOS 11.3 i can no longer find the 5GHz wifi and can only connect to 2.4GHz wifi. I observed also that when browsing at wifi 2.4GHz I experience some lag and slow to open pictures and movies even I'm using 20mbps wifi bandwith. I did try restore my Iphone to new device, (erase all data reset to factory setting) yet there no 5GHz wifi.I don't have experience like this when I'm using IOS 9.3.5. Please help. Thank you so much.
iPhone 6 Plus, iOS 11.3