Did you try the network reset option first?I have an ATT model and I never see the wifi with the + symbol up top ever. ATT said I should be good to go. I guess I need to do a factory reset. What is the best way to back up and restore to get the phone as close to back to my current setup as possible. Samsung backup?
But yeah use Samsung's cloud backup. Works really well. Maybe just don't restore phone settings just in case it brings back the issue.