Changed LDAP Server - Users Login but Old Data is Gone?

Nextcloud version (eg, 20.0.5): 25.0.3
Operating system and version (eg, Ubuntu 20.04): Ubuntu 22.04.1 LTS
Apache or nginx version (eg, Apache 2.4.25): 2.4.52
PHP version (eg, 7.4): 8.1.2

The issue you are facing:

We recently migrated our AD server and reconfigured our LDAP settings in Nextcloud. Users can authenticate fine but when they do, they are treated as a new Nextcloud user.

It would appear there’s some behind the scenes mapping - their data still appears to be present but unsure how to fix the mapping issue that appears to have been caused by the new LDAP config/AD server.

Any thoughts?

Thanks

Is this the first time you’ve seen this error? (Y/N): Y

I would recommend to you the User Migration app.