Using an iPhone 6S, iOS 12. Had the same problem with iOS 11. Basically, Wifi switches in iOS have a mind of their own. I turn it on/off in the control panel and it spontaneously changes itself 10 seconds later. I log into the settings to switch the wifi, and often it won't even allow me to turn it on. The switch will behave like it is frozen or locked off for some reason. Then, 5 minutes later it will allow me to switch it on. Sometimes, Wifi will be turned on in the control panel, but then I go to settings and it appears to be off. It really makes no sense and it is very frustrating. Is anyone else having this problem? I am thinking of upgrading to the iPhone Xs, but if it's going to have these same problems I may re-consider Apple products entirely. It's just the most annoying bug I've ever seen. I had thought jumping from iOS 11 to 12 would solve it, but it appears not. Some have said that it's by design to behave like this. Any thoughts about it? Is it due to having an older iPhone? Does the Xs have the same problem?