Is Garmin Express supposed to work with third-party ANT+ dongles, or only the official Garmin one?

2196702 said:

Garmin Express doesn't see it when I try to add it as a device.

I'm not sure if a third party dongle should work with Garmin Express, but you don't add a dongle as a device to Garmin Express. Instead, after plugging in the dongle, you add the device you want to communicate with, i.e. for example a watch. What specific device do you want to connect to Garmin Express over ANT+?

Apparently, ANT dongles are supported, but I'm just not sure that a third-party one will work. It hasn't for me.

From what I understand, it allows you to sync your device without needing to sync with the Garmin Connect App (which has to be open for it to actually sync data from my watch).

It would add convenience, but it's not critical.

2196702 said:

From what I understand, it allows you to sync your device without needing to sync with the Garmin Connect App

But this only works with very limited selection of devices. Specifically, most current watches DO NOT support ANT+ syncing. So tell us which watch do you want to sync over ANT+, and we'll tell you if this is possible or not.

My current garmin devices include the Venu SQ, Instinct, an Edge 840, and HRM Pro, but I plan to add more and/or upgrade devices as I go.

If I have to use a Garmin ANT stick, then it'd be nice to know. If not, I'd be interested in knowing how to get a third party ANT dongle to work.

None of your devices supports sync with Garmin Express over ANT+, so neither the original garmin dongle nor a 3rd party dongle will work for you.

Perhaps I haven't been clear in my question. I'm not asking if it's compatible with any of the devices I own. I'm asking if a third-party ANT dongle is supposed to be able to pair with Garmin Express. If it's not, then I don't worry about it. If it is, then I'd like to know what steps to take to get it working.

Another way to look at the situation is to check the specifications of the ANT+ dongle and see if they address use with Garmin Express. 

While they don't explicitly say Garmin Express, they do list Garmin software and Garmin devices, as well as other platforms (like Zwift) for compatibility.

They do say that this dongle has the same compatibly as the Garmin 010-01058-00 & 010-10999-00 ANT sticks, so I wonder if Garmin Express can only work with a Garmin ANT stick.

My question is more about whether Garmin Express actually supports third-party ANT dongles or not. The pairing process doesn't specifically call for a Garmin device, only "a device, ANT stick or memory card.".

2196702 said:

I'm asking if a third-party ANT dongle is supposed to be able to pair with Garmin Express.

You don't understand how it all works. You don't pair an ANT+ dongle (Garmin or not) to Garmin Express, just like you don't pair a USB cable to Garmin Express. The ANT+ dongle is just a medium for pairing select wireless devices to Garmin Express. So in your case it doesn't really matter if a 3rd party dongle is compatible with Garmin Express or not. Even if it is, you won't be able to do anything with it, because you don't have any device that is capable of ANT+ syncing.