Active Directory Password Synchronization

(I'm still on Mojave)

My MacBook Pro is managed using my company's Active Directory system. When I change my password locally on my Mac, the change is reflected in the AD server, and all is well.

Last week I changed my AD password by changing my local Mac password. Fine. But afterwards, I had to restore the whole contents of my disk from a Time Machine backup which was done _before_ I changed my password. As you can guess, I got back to the previous password on the Mac.

Now I find that I can't change this password locally on the Mac to synch it with the (new) AD password. Whenever I try to do that—both when connected to my company's internal network through VPN, or when "mobile" on the Internet—, the system says something like "Can't change the password because the server is unreachable, retry later when it's available".

Can anyone help me re-synchronize the local and AD passwords?

Thanks in advance,

Martin Jourdan