keyboard shortcut bug?

latest C10.5 version
after setting the keyb shortcuts for Vertical Zoom IN+OUT to shft+G and shft+H (see att. pic)
Cubase does not respond to those key commands.

looking in the corresponding menu entry (same picture) there is no indication that those functions have a shortcut assigned.
operating from the menu command the functions zooming in and out vertically works.

any idea?