Lately my Note 3 switches to WiFi whenever it recognizes a WiFi network like at home or work even though I have WiFi turned off and Smart Network Switch, or whatever it's called, not activated. Anyone know how to fix this?
Do you have WiFi manager connection assist turned on in the T-Mobile account app? Do you have the Passpoint option turned on in advanced WiFi settings? If neither of those, you probably installed some app which is doing it.
Look for an app that's doing it. There are lots of apps that do this type of thing - battery/power saving apps, task managers/killers, automation apps, optimization apps, sync apps, and of course wifi apps among others. Go through your apps and check settings. If you need to narrow it down, see what's in the running applications list (including the cached processes) when this happens.
Edit: I see you found your problem app while I was writing this up.