traitOverrides.horizontalSizeClass = .compact Works but not if you want to see more than 4 tabs at the bottom. traitOverrides.horizontalSizeClass = .unspecified Works if you want to see more than 4 tabs at the bottom.

traitOverrides.horizontalSizeClass = .compact If you use .compact and your app has more than 4 tabs the 5th tab will have a More... option, which is not what you want. To restore the same functionality you have to use the following traitOverrides.horizontalSizeClass = .unspecified traitOverrides.horizontalSizeClass = UIUserInterfaceSizeClassUnspecified;