Not sure when this happened but editors has noticed that you no longer can choose page from the page tree anymore on ContentAreas when selecting "Choose contentt" (Välj innehåll på svenska).
The workaround is of course to drag and drop the pagefrom the tree but I wonder if anyone knows when and why this was removed from the popup.
Images show what happens when you click "Välj innehåll" on an ContentArea that allows ArticleBlock and ArticlePage.

Regards

Linus