My guess, not quite sure if I'm correct but you may need extenders supporting a mesh.
Otherwise if you have two WIFI extender available it is worth a try.
Alternatively ESP32 support Wifi Mesh. Sp it is cheap and also worth a test. It is worth to check if Tello Wifi is compatible in a Mesh, too.
Haven't the time yet to check with my NodeMCUs?
I've tried the esp32 and the esp8622 over the last few weeks, adding extra wasted boards to my stockpile lol, both do not have enough speed Mbps (the esp32 is between 3 and 5 from what I've read) to carry the video feed it seems. Both come out with the same errors of missed packets. The distance is certainly there tho, just not the speed needed for the TELLO.