When I initially tried to bind the UMX Ultrix to my transmitter (Radiomaster Tx16S Max) I had a curious problem.
I followed the binding process as per the manual. After a few seconds the tranmitter seemed to be bound OK (It stopped beeping and the binding indicator went out). The receiver still continued slowly flashing blue though and would not respond to any controls.
If I unplugged the Ultrix battery I got "Telelmetry Lost" from the transmitter and then "Telemetry recovered" if I plugged it back in again. If I went to the telemetry tab in model setup and clicked "Discover sensors" a load of telemetry data was displayed. I still continued to get the slow flashing blue LED and no control response on the Ultrix though.
I tried re-binding with the Ultrix further away and also with different transmitters (A JumperT16 pro and a Spektrum DX7S). In each case I got similar results with the Ultrix remaining in bind mode and not responding to controls.
I tried searching the RC forums and wider internet but I could not find any resolution, or even anyone reporting a smilar problem.
All this was done in my workshop / home office where there are a number of computers and other Wi-Fi devices.
I decided to take the transmitter (Radiomaster) and Ultrix into another room where there would be less 2.4GHz noise (the kitchen) and try again. This time everything worked perfectly.
In hindsight I think that a number of binding problems that I have had in the past might be related to the noisy 2.4GHz environment.