I have had a Garmin 550 for many, many years which I have had connected to my Interphone F4 and it has always been fine. I recently bought a new Garmin 396 LMT-S but I have failed miserably when I try to connect it by Bluetooth to my Interphone F4. I was wondering if the 396 is incompatible with the older Bluetooth system? Anyone with any experience that can help? Thanks in advance.