It’s wild that "verify existing passcodes remain inputtable" isn't the absolute first item on the QA checklist for any keyboard layout change. The Czech layout isn't exactly an obscure edge case.
The USB keyboard suggestion mentioned in the other comments likely won't work either because of USB Restricted Mode. After an hour of being locked, iOS disables data over the Lightning/USB-C port until the device is unlocked. It’s a perfect, recursive failure: you can't unlock the phone because the character is missing, and you can't plug in a hardware keyboard because the phone is locked.
Treating the passcode keyboard as a transient UI element that can be "cleaned up" rather than a hard security dependency is a massive architectural oversight. If the OS allows a character to be used in a passcode, that glyph needs to be permanently accessible in a fallback mode, no matter what the localization team decides to prune.
> The Czech layout isn't exactly an obscure edge case.
From what I understand, the problem wasn't with typing characters actually used in the Czech language such as á, ř or ů. The problem was with typing the ˇ character by itself, which is normally encoded in Unicode as U+02C7 (CARON), but there also is a combining version (U+030C, COMBINING CARON), which is what gets printed if there is no precomposed character (e.g. š is both U+0161 and U+0073 U+030C). There is a thing called Unicode normalization that makes "identically looking" strings actually use the same codes, so maybe it was that thing that changed a bit (maybe even somewhere else and not in the lockscreen/keyboard logic), or they could have just removed the ability to type ˇ by itself altogether since it's not something actually used in any language or writing style and most often comes up as a result of a typo.
I agree with you and don't really get what Apple gets from removing a valid Czech character, but how would you test if all existing passcodes remain inputable without knowing the passcodes of all iPhone users?
The one way to do this that I could see is to include both the new keyboard and the old one and if someone fails to unlock with the new one auto report that to Apple (not the code, just that the unlock failed and that the keyboard might be the problem), then auto revert to the old keyboard on the next unlock attempt...
People have had the same issue with broken screens (and not just on iPhone).
Your touch screen stops working. You want to dump the data by plugging it into the computer. To do that, you need to click "approve" or "trust" or whatever on a touch screen. A touch screen which.... stopped working.
We have definitely moved much, much too far towards security on the security vs. convenience tradeoff. We need a "I am not a human rights activist, I neither understand nor need all of this stuff" mode.
In my book this is proof that Apple has lost control over QA, which is a massive failure, not just some minor hiccup. This has degraded the iPhone from an important tool you rely on to a toy you can afford to lose any second. Everyone needs to draw their own conclusions from that.
AI slop bot go away
If I'd get a dollar for every annoying bug that Apple misses due to being hopelessly Bay Area brained, I'd probably get at least a free official Apple cleaning cloth every couple of years.