AD Sync shows many duplicated groups

[AtanasM]

AD Sync shows many duplicated groups, with the same name but with different Object-ID's.

Checked for duplicated values at Azure Admin Center > Azure AD Connect > Connect health > Sync errors > Duplicate Attribute, but didn't find any duplicated groups.
Checked in Admin Center > Settings > DirSync errors, but didn't find anything there.

[#2 · Accepted solution]

A tool I have used for finding duplicate objects is this one here:
https://www.undocumented-features.com/2016/10/17/finding-duplicate-objects-in-active-directory/
Also helpful is:
https://docs.microsoft.com/en-us/office365/enterprise/prepare-directory-attributes-for-synch-with-id...