Hello there,
This flag on an account may be an indication of a stale account or an account created without a password.
User accounts can be flagged with pwdlastset=0 under three conditions:
Where an account has been created but a password has not been assigned.
Where an account has been created and the administrator has assigned a password but selected the option to change password at next logon.
Where the administrator has selected the option to require a user to change their password at the next logon as part of managing that user’s account, such as after a password reset.
Review accounts where the attribute "pwdlastset" has a zero value https://learn.microsoft.com/en-us/services-hub/health/remediation-steps-ad/review-accounts-whose-attribute-pwdlastset-has-a-zero-value
Hope this resolves your Query !!
--If the reply is helpful, please Upvote and Accept it as an answer–