I've deleted the old test configuration and simply created a new one, cause I couldn't even open the file in as a source code in the latest Xcode 26.4.

It seems there are no working workarounds, setting appearance for the textfield doesn't work either. The only solution for now is to use a different keyboard type. Bug reported - FB22193091 Thank you

Same issue in SwiftUI while using .keyboardType(.numberPad) in combination with .preferredColorScheme(.dark). I'm afraid it's iOS / iPadOS bug.