echo can't find devices ....

[mjz]

My echo is connected to my wi-fi network. Lately, it can no longer find my devices (honeywell thermostat). It used to work, but suddenly it's no longer "visible". When I use the app to find devices, none are found.

The wi-fi thermostat is working fine. I can connect to it via my phone or other computer devices.

Help?

I have an AT&T Pace 5268ac router. It does not support UPnP, but that did not seem to matter before. Any suggestions?

[tuicemen]

Have you used the search feature here ,top of page?
Using "echo stopped" I found several threads.
Did you try any of those suggested replies?

[malliekm]

You've probably already tried unplugging your Echo for 5 minutes and reconnecting.  Sounds like everything is working on the router end but you could try removing the thermostat and reinstalling it.
Which model Honeywell thermostat do you have?  I'm thinking about getting one.

[mike27oct]

When devices that are known cannot be found, you need to ask alexa again to "discover devices".