First I would try the system driver to see if that at least works correctly, then you will know if it is a device problem or a driver problem.
I suspect the custom driver you are already using is the one Minoston has posted on their site since the one you linked to above is made for Smart Things and would not be possible to install on Hubitat without modifications: Firmware/Drive | Minoston |
You could also try my ZEN04 / Universal Power metering driver: [DRIVER] Zooz Smart Plugs Advanced (ZEN04 / ZEN05 / ZEN14 / ZEN15)
It was made for Zooz plugs but I have coded in it a way it could be used for any Zwave plug that follows the specs. It does not do the energy cost calculations but there is another app which can do that or it is very easy to o by hand using the energy and duration info.
