Fibaro Walli Roller Shutter partial closure?

Hello there, not sure if it’s the correct category ?

I’d like to create some automations using partial closures of my shutters.

Using HA Green latest version, UZB stick and official fibaro walli and classic roller shutters.

I tried using this first and choose my percentage

and it does nothing
see response

Am I missing something ? Is that even possible with those Fibaro ?

Thanks a lot, have a good day