Garmin 500... attached via USB. Makes a beep (gets power from USB), your software will not acknowledge the connection.
I've been trying to use Garmin products for the past 20 years and it has been an absolute struggle. They have repeatedly and consistently failed me in the hardware/software interfaces. I'm done. I will be removing all of my Garmin cycling sensors, head units and computer mounts from all of my bikes. I'll also be binning my running sensors, 3 heart rate monitors and tossing my 2 Garmin watches in the trash. After my purge I'll be heading out to invest heavily in another brand's offerings.
Thanks for all the fish.