rs3, I tried Ctrl+Page Down and clicked the Down icon to the left of Page m of n.
As you say, double-click on any page works as you are then in Layer mode.

And Yes, it is a Bug - moving to Dear Xara.

In the new UI, the page name of the pages move from the bottom to middle right when moving from Pages to layer view - widen your Gallery.

And Yes - not really thought out.
It still needs a Page/Layer toggle button.

Acorn