At the Fez branch, new accounts and passwords changed at head office do not work

Sakane Distribution, a building materials wholesaler, has its head office in Casablanca and a branch in Fez. The sakane.local domain has two domain controllers:

On Thursday 15/10, the network contractor replaced the Fez branch router and changed the addressing plan: DC-FES-01 moved from 192.168.20.10 to 10.30.0.11. He “cleaned up” the DNS console by deleting the records of the old address.

This Monday, three tickets: the new Fez sales rep, Youssef Tazi, cannot log on (his account was created on Friday at head office); Salma Berrada changed her password in Casablanca and the old one still works in Fez; a GPO changed on Friday is not applied at the branch.

You are logged on as domain administrator on DC-CASA-01. The VPN between the sites is working. Restore replication without demoting or rebuilding a domain controller.