My original Aeotec parameter list must be very old. Every other nano dimmer list shows that the value should be 3 for momentary. Let's check your setup.
Change the device driver for your dimmer to Basic Z-Wave tool.
If your switch is wired to Com and S1 then enter 120 in the Get Parameter Report:
If you switch is wired to Com and S1 then enter 121.
Click 'Get Parameter Report and look at your logs. You should see a line like this:
[dev:83] 2019-05-28 09:30:21.880 am [info]ConfigurationReport- parameterNumber:120, size:1, value:1
I'm using a regular light switch so my value is 1.
