The BLE signal is often detected by the Edge first when pairing. It can take a little longer for the ANT pairing to to show up.
If you are currently paired to the sensor over BLE. Go down to the sensor details and untoggle the enabled setting so that the Edge will not pair with it. Then do a new search for the sensor type you want. The Edge should then show the ANT option for that sensor as the BLE option is already in the sensor pool and disabled.
I have a new Stages L power meter that is paired via BLE. Is there even any reason I would want to use ANT+ instead?