Yes, I used a Xiaomi Mi WiFi+ repeater attached to a usb powerbank to boost the wifi signal between the phone and drone - this compensates for the Bluetooth interference from the controller. (Not a great solution but it seems to work).
No problem, it does seem a bit silly to have to buy all these extra gadgets but I guess the Tello wasn't really designed to be flown from a Bluetooth controller and we are all expecting a little too much from it. That said it can be made to work and does it pretty well and the wifi extenders are pretty cheap (and can be used for other stuff too) so its not all bad
Just for comparisons sake I did pretty much the same flight test with a DJI Spark using the DJI controller
(yes I had my big boy pants on to fly this beast indoors in such a small room but using the controller it seems to be much harder to fly face first into a wall)..