Group management in eDirectory is different from Active Directory group.
The group has two attributes of interest (member and equivalent for me), and the User has two attributes of interest (group membership and equal security levels).
Adding a user to a group updates all four of these attributes when executed correctly.
Security / equivalent attributes are the mechanism by which rights and proxies are processed, so you can skip them if they are not used inside eDirectory, but better if you do not.
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