Leviton stopped responding

I have been using Z-Wave for years and using the separate Z-WaveJS UI for managing it integrated into HA. I used Leviton Z-Wave switches thruout the house. Today one of the switches, though still working on the wall and showing a green light when off, isn’t responding thru HA. it’s giving a status in HA of Entity Not Found. In Z-WaveJS UI I do not believe it’s showing. Thoughts? Tried holding the up toggle on the light switch until it turned yellow and then turned it off but no joy.

Note i did hold it until it turned red and then held it again until it turned amber (inclusion mode). I kept trying to include it but no joy. I know these are electronics but what are the changes that just the Z-Wave part fail?

Also can you use a Z-Wave 800 device on an existing network? I assume my network is 700 based. Amazon doesn’t seem to have the same device anymore. I have the DZ15S-1BZ and looks like now they have ZW15S-1RW

I have a Gen5 stick. Z‐Stick USB Controller ZW090