Inovelli Dimmer and Smartthings V2 One works one doesn't

I know this has been tossed around before in this forum but I can’t seem to get it to work.
I bought 2 Inovelli dimmer NZW31 switches. I have one working fine but the other will only work by using the switch.
They both have the identical setup.
The one that works is in the same room as my ST hub.
The one that does not work is up stairs (So through a floor and a couple of walls.)
So I figured that was the problem so I have a “Ring Chime” with a built in wifi extender .
So I put that within a foot from the switch that doesn’t work thinking it couldn’t pick up the wifi.
But it made no difference.
I’m no Einstein with this stuff but with doing that it should have work??
I need these to be reliable or their no good to me.
Any thoughts or did I get a lemon on one of them.
Thank you in advance.

The Inovelli switches don’t use Wi-Fi. They use Z wave. Different frequency, different protocol. So you need to have a Z wave device that can work as a repeater in order to get signal up to where the other switch is.

Read post 11 in the following thread, then go up to the top of the thread and read the whole thing and it should answer most of your questions. (This is a clickable link)