Good evening Max,
You can explain why the program display shows the speed of the trainer and registers another speed in the display.
Thanks for the answer
The speed of the trainer is simply the speed recorded with the ANT+ sensor from your rear wheel.
The speed shown by default is the "virtual speed", calculated in real time to have an estimate of what would be your real speed in the outside world. It is possible to change the default speed in the workout options if you wish.
This speed is calculated with your Power, your weight, and other parameters set in your profile.