Somfy ZWave Blinds (Dimmer)

I tried this driver; while seem to be able to talk to the shade & fetch info just ok, but it is throwing an error when I try to open/close/set position.

I even got hold of the driver code from ST and compared it what @DeveloperDavidB had posted in this thread. Everything checks out - only changes are color and replacing 'physicalgraph' with 'hubitat' (See comparison), so not sure why is it not working for me?

I am really struggling to have my shades work, so any help will be appreciated.