
To resolve the issue of additional users unable to log in to your private Power Pages site:
Check User Roles: Ensure that each added user has the appropriate security roles assigned in Power Pages.
Review Registration Settings: Verify that site registration settings allow new users, and ensure no settings are blocking additional user registrations.
Invite Users with Correct Process: Double-check the invitation process, as misconfigured invitations can cause login issues.
Limit of Active Users: Ensure there’s no restriction on the number of users allowed access.