Problem with user authorization by CAS - ObjectGUID attribute

[Irkhar]

Nextcloud version: 25.0.7

Hello,

We have a nextcloud service in our company with the "LDAP user and group backend" plugin installed, which had default settings when the service was launched. People who logged in to the service have a username after the ObjectGUID attribute.
The problem appeared when authorization was started by CAS using the "SSO & SAML authentication" plug-in. The plugin does not use the ObjectGUID attribute for UID mapping.
Is there any possibility to run authorization after CAS using the ObjectGUID attribute? Maybe there is some tool to migrate from ObjectGUID to e.g. User Principal Name (UPN)?

[blizzz]

User IDs in Nextcloud are immutable, and the IdP has to provide the same id for the same user logging in.