“Your Detail View Controller interface may have misplaced views now that it is contained within a navigation controller. If it does, select the stack view and click the Update Frames button in the Auto Layout constraint menu.”
Update Frames is ‘greyed out’ or unavailable after selecting Vertical Stack View. To get the frames to update, I clicked on the Detail View Controller, then show Attributes Inspector. Unchecked and checked “Under Top Bars” within the View Controller > Extend Edges section.