I have just tried. It only finds the home wifi, not the tello.
The phone shop found a small set of wifi security protocols on the Tello which my phone did not display. Two phones they tried displayed one or more of them. One of their phones did not display any so it could not link. They also had a dji Mavic there and it had even more protocls, none of which my phone had.
Does this make any sense?
I have to admit that I have no idea what you mean by "The phone shop found a small set of wifi security protocols on the Tello which my phone did not display ". There is no such thing as security protocols with tello.
I have a handful of devices here from Android 5 to Android 9 and three different Tellos and none has trouble.
Can you explain exactly step-by-step what you are doing and what does not work? Or post a screenshot?
What a stock Tello does: It shows up as a plain wifi access point with an SSID like "TELLO-AC4355" and no paswort set. Any normal phone (or PC, tablet,...) can connect to this wifi, even multiple in parallel.
I get an available WIFI network TELLO-AC214F
I click on it and it gives me messages
Check the quality of your intenrt connection
Internet may not be available
The Tello light is flashing orange throughout and then eventually stops (timeout?)
The "internet connection" warning appears because your device is attempting to connect to some web-based service, which will fail (of course) because you are connected to the Tello. I get the same warning and it is not the problem.
The Tello may indeed be timing out because it gets too hot if it stays on too long without flying.
Once you are connected to the Tello, then open the Tello app. What happens or what do you see then?
What JBTello says!
Whenever you connect to a wifi access point that does not offer access to the internet Android shows a warning. Of course Tello does not offer an internet connection so just accept this message.
Afterwards the Tello App on your phone should connect. If not just de-activate cellular data but then it should definately work.
The phone has connected, the app has hooked in and the Tello has flown a short flight.
Maybe it was just slower to connect than the other phones. I never really understand what the phone guy said about the security protocol not being present.