I have a J7 (SM-J730F/DS) and noticed a while back that I can connect to WiFi but that on some networks I got the message "Internet may not be available" .... and it wasn't. This message started to appear more and more frequently and on a trip last week I could not connect to any airport, hotel or other WiFi network, with the exception of 1 network at the conference center. Upon return home, I now also get the message at home and at work. Using data roaming to get on the net is not a problem.
I searched the web and found a number of potential fixes. I did the following:
Reboot (didn't solve it)
Forget network, then retry (didn't solve it)
Switch to static IP (didn't solve it)
Changed time/date and then back (didn't solve it)
Cleared Cache Partition (did't solve it)
Factory reset (didn't solve it)
I'm now out of ideas. Anyone any suggestions?