Most android box remotes have a "mouse mode" which is required to access these menus as with some apps they do not recognise the normal Dpad directional buttons. The problem is that this mode is purely a point and click interface and does not allow for a scrolling functionality.
I have spent much time trying to resolve this frustrating problem and then I came across an instructional video on You Tube and it works !!!
Here’s a link
Please ensure that you do the actions in the exact order as described. I assigned the toggle to my numeric 8 button on my remote. Press once for mouse mode, once again for scrolling, press again to return to mouse mode or long press to remove the toggle.
It is superb and I now have no need for using the ‘mouse’ button on my remote.
Hope this helps anyone with the same problem.