I understand that you are receiving the 33007 "The password given does not specify the user's current password" error on the AD Connect server.
Here are a few possibilities and steps to try:
1)Please verify if the password writeback access rights are present on the object and that "Enable Inheritance" is selected as detailed here: Troubleshoot password writeback access rights and permissions - Active Directory | Microsoft Learn
2)Please verify that password writeback is enabled in AD Connect and in the portal, and that there aren't any password policies blocking the writeback. See additional troubleshooting steps in the article: General password writeback troubleshooting steps - Active Directory | Microsoft Learn
3)This can happen if you have the preferred DC configured using NETBIOS and not FQDN.
Please check under Synchronization Service Manager > Connectors > open the Active Directory Domain Services window > Configure Directory Partitions > and under "Domain controller connection settings", and make sure you have the FQDN of the DC(s), if not have them change it to FQDN.
4)Ensure that the AD DS Connector account has all necessary permissions. You may need to try changing the password on the account in AD DS and then try to change it in the admin portal. https://learn.microsoft.com/en-us/troubleshoot/azure/active-directory/password-writeback-access-rights-permissions#root-default-permissions-for-the-ad-ds-connector-account-allow
If none of these steps help, feel free to reach out to me at AzCommunity@microsoft.com ("Attn: Marilee Turscak") and include your subscription ID and a link to this thread, and I can enable a one-time free support case to look into this issue.
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