Trouble pairing Tacx speed cadence sensor

I have bought the Tacx Speed and cadence sensor but I have problems pairing it with my iphone or ipad. I am able to see the sensor as a unit in the training app, but cant see any advice when I check the bluetooth units in settings on the ipad or iphone ( have there been a connection when the senosor appear as a unit in the app?) Will attach a few pictures from the installation and the Tacx training app. Its very narrow between the frame and the crank arm., so had to install the cadence sensor on top of the frame , not on the side. Will this cause a problem? When I installed the battery I got some blinking on the bluetooth transmitter. Is there any way to «start» the sensor?