Password change issue

The last weeks we experience issue with users changing passwords.

User are created on premise in the Active Directory and synced with Azure AD connect (where are still running version 1.2.70.0). New users get a temporary password which they have to change on first logon.

Our users get devices which are setup through autopilot. They get prompted to change the password but when they do they get a message that the password is changed but that servers have process this change, resulting in issue that user cannot continue to setup the device. As a work around we tell them to turn of the device. They then can continue through the autopilot process because the password is already changed.

We use PTA and PHS still enabled. We moved form ADFS with PHS in June this year to PTA. We didn't have this error the first month after this change.
The error we see in the audit logs is OnPremisesSuccessCloudFailure.

So it seems there is some kind of delay after password is changed on premise.

I cannot anything on this particular error