Don't briefly show the sidebar if it's going to be hidden

I have wallmounted tablets with the sidebar set to disabled (because it takes up too much space / gives access to pages I do not want on there)

Whenever I see them refreshing (e.g. when they lose connection or are asked to do so by an automation for instance) I see the sidebar-area showing up for a moment with a white area. Looks ugly, afterwards it disappears but would be nicer if it didn’t show up at all if it is disabled.