Mapping of group roles from LDAP to Keycloak

Hi all together!
I’m using Keycloak together with LDAP/Active Directory and have roles in LDAP (modeled as groups) which are associated to users and to groups, thus all members of these groups should get those roles during import/synchronization. Unfortnately those roles are imported but the membership to the groups not. It works fine for the users having those roles, thus I would say that my configuration in Keycloak must be probably correct.
Is this a known bug or/missing feature or am I doing something wrong?
I would appreciate your help very much because this quite urgent for me.

Thank you in advance!