Groups_claim of on premises AD Oauth2

I have configured my vault and connected it with my on-premises Oauth2 and AD. While creating grup_claims in response I am getting

identity: refreshing external group memberships: entity_id=9 group_aliases=["mount_accessor:"auth_oidc_e1998574" name:"group1,group2,group3""]

While creating an external group in the vault and creating an alias with group1, No policy is getting attached to it. Also if I create Alias name as “group1,group2,group3”
The policy is getting updated for users.

I can’t change the response from AD or Oauth2. How can I made changes in the vault to solve this issue.

Thank You.