Have you confirmed that your Rx 5 is bound to your Tx, i.e. will it operate a servo if powered up.
Also what flight simulator are you using, if it is one that requires a dongle, e.g. Pheonix, then that will also need to be plugged into the adapter as per the instructions.
Lastly is your computer recognizing the adapter and using the correct USB port in the flight sim, i.e you might have the adapter plugged into Com port 5 and the simulator is looking for a controller on Com Port 7