Question about VoiceOver not reading password field label

iOS and iPadOS
Hi all, I have username & password fields with client side validation, on-blur on username will have client side validation and voice over reads validation alert message in safari browser with (role=alert or aria-live="polite" or aria-atomic="true") eventually when I enter tab focus will move on to password label but password label is not read by voice over on focus on it after reading error validation message on username. This issue happens with NVDA screen reader as well(nvaccess team accep this defect).Could anybody please let me know reason for this behavior? I have seen similar issue in apple website as well.Here is the link where voiceover reads username validation message but does not password on focus . Username Enter Username here Enter username Password Enter password here Enter passowrd