I am having the same wifi connectivity problem. Talked to the AT&T tech, and they told me to refresh, hard reset, and after 2 hours on the phone, no avail.
Then they referred me to the Samsung technician, and I spent another hour on the phone with them, and did the same deleting user profile, factory reset and they started a work ticket.
Then I went to AT&T warranty center, the jerk there told me, "well, looks like wifi will turn on, you just have to turn mobile data off everytime you're near a wifi location. You found a solution on your on by turning off mobile data. You're lucky you're a smart girl. Keep doing that method." What?
I then said, "wait, so if a car's brake malfunctions, will the auto manufacturer say, 'just use emergency brakes' until we can figure it out."
He responded, "yes, that's right."
Wow...