Here is my Way Too Much Information

Post on mobile devices and WiFi. When a phone connects to WiFi it needs to determine if you are on a “captive” network. This means that you don’t have full network access until you agree or do something in their captive webpage. This might be agreeing to some T&C’s or logging in.
To detect that, they connect to a known address over HTTP (very explicitly NOT HTTPS). For Apple it is
http://captive.apple.com. Google has something similar. If they are able to connect successfully, then they know they have a “good” connection. If they instead get redirected elsewhere, they know they need to pull up a browser pointing to the page they were redirected to.
Sometimes this process fails for whatever reason. Sometimes WiFi networks are dumb and they let those connections through. Or maybe the phone accidentally loads a cached copy. Who knows. Regardless, the phone thinks it has an Internet connection and stays connected to WiFi but traffic isn’t going anywhere.
My fix for these situations is to have a NON-HTTPS address bookmarked. Most sites these days not only use HTTPS but even if you try to go the HTTP version you will get redirected to HTTPS. My preferred site is
http://neverssl.com/. If you open a browser and go there, the WiFi network should properly route you to their page for logging in or continuing or whatever nonsense they want you to perform.
Note that this may not have been your problem at all (Disneyland WiFi is notoriously awful), but it can help in determining if you have a real connection or not.