Calling Open Level when using World Composition

My main map uses World Composition. When I run it directly in the viewport, everything works fine.

However, when I switch to using a MainMenu (still using the viewport), after calling Open Level (by name) on the persistent level from OnClicked, the Pawn ends up below the initial sub-level. I can’t tell if the whole level has moved up in Z or if the player fell through.

PlayerStart is positioned in the persistent level. The persistent level and all sub-level files are located in the same folder.

I also see this problem when I run in standalone or packaged mode, with or without the MainMenu level.