Please enter the simulator pairing menu, and in the main screen, click on Forget my devices and unlink them. Close the simulator program entirely. Make sure that the sensor is not paired via Bluetooth to any other device or app, because in that case it would be invisible for the rest of computers or tablets.
Bluetooth allows one only connection at a time. Please check this out in case of Android devices: go to Settings -> Applications -> BKOOL Cycling -> Permissions and enable the location permission.
Then open the simulator up and try the pairing again, the ANT+ and Bluetooth icon should be highlighted. Pair the sensor and then the trainer as the main device, etc.
If you still do not detect it, you can also reset your sensor, go to the manufacturer's website and you will find a way to do it, in many cases you must place the battery upside down and press it for a few seconds.