I have 25 Tellos and my students can connect every time with an iPhone. Several of my students only have Android based phones. Most seem to be able to connect, although, none of the students that have Samsung S20's or newer can get it to work. We have read forums, and tried several of the suggestions, but nothing seems to work correctly. The minute an S20 tries to connect, the light turns yellow on the Tello and there is no camera view from the app. You can swipe to hover but nothing happens. But, if you go to the wifi settings, it shows it's connected. We've tried to connect to at least 15 of the drones, same reaction.