Dimmer that won't shut off

So just installed another dimmer switch, a Levition Vizia RF+. Unfortunately it won’t turn off! Just pressing the switch, it ramps down then “bounces”, ramps back up to the same dimming level.

Switch is controlling some under-cabinent halogen lighting, replaced a standard dimmer. Anyone see anything like this before? Bad switch or do I maybe need a different type of dimmer switch for these lights ?

Thanks…