Dropdown should be hidden but is visible

I have a dropdown by index component which has it's visible attribute bound to the context attribute DISPLAY. DISPLAY is set to cl_wd_uielement=>e_visible-none in the supply function. The dropdown should be hidden dynamically.

However, when the component starts the dropdown is visible which is incorrect. The debugger shows that the context DISPLAY is e_visible-none (01). When a pushbutton is clicked, the dropdown disappears. It seems that the form is rendered before the supply function sets the DISPLAY element to e_visible-none. Is there some way to force the form to "repaint"?