Hi @schuess3 ,
Do you mean that you can not get all members of your group?
Please check these things:
1)the group is an office365 group
Office365Groups.ListGrouMembers function could only get members from office365 group, not supported sharepoint group.
2)Office365Groups.ListGrouMembers function could only get at most 100 memebers
This connector's limit.
3)Does your talent has more then 500 users?
This problem may be related to deleagtion.
If records in data source are larger than delegation limit, you may get wrong result.
Please change the delegation limit to 2000.

If your talent has more then 2000 users, changing this limit will not resolve this problem.
Maybe you need to consider using collection.
Best regards,