I was able to get the Leviton D215S switch working again, I'm sharing what I did as it may be of help to someone else. First of all, I think I had several layers of problems:
- The new Orbi mesh comes with IPV6 off by default, Leviton's documentation requires this on and mode set to "Auto Config".
- Several people report connection problems with firmware 2.1.25, which is the stable version posted by the vendor. To get a more up-to-date version you need to join Leviton's "Matter Early Access Program" (join via their "My Leviton" app), and also reach out to their tech support to request a more recent firmware. I got v2.3.15. I also factory-reset the switch and reconnected to our home network, to make sure I had a clean connection.
- Some folks also report issues when using networks with 5 and 2.4GHz wifi service under the same SSID, which is the way our Orbi 770 mesh works. I'm not sure this is a relevant with Hubitat, since the box has a wired connection. Just in case, I enabled a 2.4GHz IoT wifi network option that Orbi provides and hooked up the switch there.
With these changes in place, Hubitat's matter pairing process was successful and quick.
