Settings/Connections/Menu button/Advanced. Turn off "Always allow scanning" and any "autoconnect" setting.
This is NOT just a Samsung problem or carrier. I have the LGV10 With Verizon and the same thing had been happening, I turn off WiFi,then it switches back on. So far I've been told this is a app permission problem, I deleted Instagram which allows it to control connectivity and since last night (16 hrs ago) and a factory reset the problem has not come back. What to do is factory reset, then download 1 app at a time, go to permissions (additional permissions) and see if it has control connectivity or controls WiFi. If it does then delte the app and use it only on your browser.Did you even test this?