This issue was addressed through improved state management. This issue is fixed in iOS 18.4 and iPadOS 18.4, macOS Sequoia 15.4, visionOS 2.4, watchOS 11.4. Password autofill may fill in passwords after failing authentication.
https://support.apple.com/en-us/122378
https://support.apple.com/en-us/122376
https://support.apple.com/en-us/122373
https://support.apple.com/en-us/122371
http://seclists.org/fulldisclosure/2025/Apr/8
http://seclists.org/fulldisclosure/2025/Apr/4