Upgraded to the S8+ and I like the phone so far, however, most of the time the wifi says connected but "may not have internet available." I can connect to these same wifi's with other devices. I also got a message saying that my data was out. It looks like my mobile data is on at the same time as wifi when I am connected to wifi with no error message. Any suggestions?
We're glad to hear that you like your new device! It's a great one, indeed. Let's see if we can get those connection issues resolved. We want your phone to work the way you need it to. There are a couple things that could be going on here. It sounds like a possible setting issue, but the router may need a restart as well. First make sure your Smart Network Switch is turned Off. This is under Settings > WiFi > Menu(three dots) > Advanced. On this same page, make sure "Keep WiFi on during sleep is set to Always. Those things may correct the connection issue for you. If not, pull your router's power cord out for five minutes and then plug it back in and start back up.
With regards to the data usage, those above settings will help, but you'll also want to turn Samsung's Download Booster to Off. This allows your phone to use WiFi and cellular data in tandem to achieve greater download speeds, but also results in more data used. To turn this off, go to Settings > More(under wireless & networks). These setting changes should resolve both concerns for you. Let us know if we can help again in the future!