As Hydro says, check your driver...it may have joined as a switch rather than as a dimmer, and/or the wrong driver may have been auto-selected. Also make sure you really got a dimmer and not a switch.
Presumably this is one of the newer Z-Wave Plus dimmers, in which case you can use the built-in "Generic Z-Wave Plus Dimmer" driver:
If you have Hubitat Package Manager installed I recommend this community driver:
