I bought this as a potential replacement for the garage door relays that have now gone stupid as far as reading the door position.

Anyway, this is my first Matter device. Power it on and try to discover it. Scan the QR and it asks about adding it to Universal Devices. Hit ok, then after a while it gives up.

I got it to join ONE time (the initial part), but then it threw some error (basically a 404 in a pop-up) then it simply hung on "finishing up". Never got that far again after many resets and power cycles.

Anyone have more luck? Am I missing some crucial step in Matter?

IOX/OS and Switchbot firmware are all the latest as of tonight.

9 hours ago, jduino said:

Am I missing some crucial step in Matter?

No, it's just probably not a UD Matter supported device yet. There hasn't been an updated announcement as to if UD has added more devices under the Matter ability. Since Matter support was announced by UD back in Feb there hasn't been any comment of additional items being added. In that announcement they said, "Support for additional Matter clusters are brewing as we speak." I'm guessing it's been a challenge to get more devices added.

You could open a support ticket with UD to see if there is support for this device.

https://www.universal-devices.com/my-tickets

9 hours ago, jduino said:

IOX/OS and Switchbot firmware are all the latest as of tonight.

Also, this doesn't help. Sure you added "as of tonight", but honestly version numbers are always better than just saying "latest" versions. Just FYI and consideration in the future.