This bug is still present in iOS18 beta 3.

Here is a workaround/solution which works in beta 1 to 3: Embed each UITableViewController in its own UINavigationController instead of assigning it directly to a tab. Make the UITableVIewController the rootViewController of the UINavigationController and assign the UINavigationController as the viewController to the tab. This gets rid of the 'move down' glitch, so possibly the new UITabBarController assumes the usage of UINavigationControllers in the tabs.

Exact same here

I’m also experiencing the exact same issue in the UIDatePicker in dark mode, this is still present in BETA4. Also for any UITextField in a cell or UISearchController in the toolbar in dark mode, I noticed that the "Cut/Copy/Paste" popover-box shows black text for most of the options, i.e. 'Paste' will be white, but the other options are black, same behavior as the UIDatePicker in the screenshot. It seems that any gray text is rendered black in dark mode, making it unreadable.

UIDatePicker also has this "dark text in dark mode" problem (and indeed the edit menu for any UITextField), all still present in BETA4 (in my case an Objective-C project) Also a UIMenu presented from a UIBarButtonItem in the navigation bar is behaving strangely in dark mode since BETA4. When the menu becomes visible, any 'disabled' menu option in the UIMenu is briefly shown in gray text (as it should be) but after ~1 second these menu options are automatically rendered in black text, making them unreadable in dark mode.