Android 5.1’s new “ignore wireless networks without internet” feature (which does not have any way to be toggled off) basically disconnects from wifi networks lacking internet. This will cause major issues for tech gadgets such as the Chromecast, GoPro, Parrot’s Lineup of Drones (Bebop, ARDrone, etc).
Basically all of these devices create a WiFi network that has no internet connectivity and in Android 5.1 the behavior is to automatically disconnect from these networks. I confirmed this on a Bebop and Chromecast so far as have other users.
Yikes! Wonder how many months until Google pushes out a maintenance release for this the good news is you can go into Airplane mode and still connect to these devices as workaround.