I've encountered the same issue, though in a slightly different configuration than @jwcarr's case. In my setup, it's a 3-column NavigationSplitView (sidebar + content + detail) where the content column contains a TabView with List inside (whereas in @jwcarr's 2-column setup, the TabView/List lives in the sidebar column). When I programmatically set the List selection to nil from the detail column (e.g., after a delete operation), the detail column does not pop back to the content column on iPhone (compact size class). The detail column's content correctly switches to the placeholder view because my state is properly cleared, but the column itself stays on screen. I've confirmed the version-specific behavior on simulators: iOS 26.2: works correctly (pops as expected) iOS 26.3.1: works correctly iOS 26.4 / 26.4.1: does not pop iOS 26.5: works correctly I also verified that removing the TabView and using a plain List in the content column makes the pop work even on 26.4.1, which matches @jwcarr's observation that the TabView + NavigationSplitView combination is the trigger. So this appears to be a regression specific to iOS 26.4.x that has been fixed in 26.5. It affects both 2-column configurations (with TabView in the sidebar, as in @jwcarr's case) and 3-column configurations (with TabView in the content column, as in my case). I have not found a work around. NavigationSplitViewColumn can be changed, but it doesn't work.