Binding a refractory parameter how?

Cantabile
1

Hi there

I am trying to bind the MelodicFlow pages using one of the knobs in my Swing keyboard, so I can use different scales to do a solo

Cattura
Cattura1493×939 174 KB

I select first the Current Page parameter and the dot becomes blue, but when I go to the Learn Binding window I find that the selected dot is always the Page Mode, that is not the parameter I want to bind

Any idea about the reason?