> During in-house testing, which involved taking an iPhone 16 from iOS 18.5 to iOS 26.4.1, The Register found that Apple has kept the háček in the Czech keyboard, but removed the ability to use it in a custom alphanumeric passcode. The OS will not allow users to input the háček as a character. The key's animation triggers, as does the keyboard's key-tap sound, but the character is not entered into the string.

Sounds more like an actual bug than a decision to change the keyboard layout, if this happens only in the passcode screen?