Inviting a Guest & Helpseeker users is not working in specific Cloud sites.

Issue Summary

Inviting a Guest user is not working on specific Cloud sites.

Steps to Reproduce

1. Navigate to the user menu for nonvortex sites. Similarly, you can navigate to the Directory menu in the Organization for vortex sites. (Screenshot 1).
2. Invite any external user as a Guest.
3. It will show an error "We couldn't send your invitation. Try inviting that user again"(Screenshot 2).

Expected Results

The Guest invitation should happen without any errors.

Actual Results

The Guest invitation is showing an error message.

The below exception is thrown in the weblogs

{"key":"noDefaultGroup","context":{"message":"No groups for Product: Product{productId=conf, workspaceId=12c0f432-9bbd-41cf-a14a-03a9f90fe3e3, cloudId=12c0f432-9bbd-41cf-a14a-03a9f90fe3e3} and Role: CONFLUENCE_EXTERNAL_COLLABORATOR"}} 

Workaround

• Create a CONFLUENCE_EXTERNAL_COLLABORATOR group in the Groups menu.
• You can add this group under the Guest menu with default access at the Cloud site level. Similarly, you can give it a Guest role and default access if you have cloud sites with improved user experience. (Screenshot 3).
• Invite the new user as a 'Guest'.