Why Google Workspace synchronised users are getting error "You’ve stumbled on a restricted space?

[Michael]

We are using Atlassian Access, Confluence on the free plan. Users that have been synchronised to our site via Google Workspace integration cannot access any spaces, persistently getting the error "You’ve stumbled on a restricted space" when they browse to any space URL. 

We have done roughly the following:

1. Created a Confluence site.
2. Set up Atlassian Access integration with Google Workspace.
3. Created a group in Google Workspace called Atlassian users and added several users to it.
4. Resynchronised with Google Workspace to confirm the new users are showing in Atlassian Access in the Atlassian users group.
5. In Atlassian Access, used Products - Product Access - Confluence - Add Group to add Atlassian users to Confluence.
6. Confirmed under Atlassian Access - Products - Users that the new users added from Google Workspace show up in the user list with status "Has site access".
7. Using one of the new users, authenticate via Google and try to go to a space URL e.g.https://mycompany.atlassian.net/wiki/spaces/XXX/overview and received the "You’ve stumbled on a restricted space" error.

If I explicitly add one of the synchronised users to the confluence-users-mycompany group via "Atlassian Access - Products - Users -MyUser - ... - Add user to group",, then that user gets immediate access to all spaces.

I am aware that we can't change per-space permissions due to our being on the free Confluence plan. Incidentally, if I go to Spaces - My Team Space - Space Settings - Space permissions, I get the message "You're on the free plan, so you can't change the space permissions", so I click the link "Grant all users permissions for this space". This still doesn't cause users belonging to the Google Workspace synchronised group to gain access to the space.

It seems the only way for a user to have Confluence access is for them to be individually added to the default confluence-users-mycompany group, even though I thought I could grant Confluence access to their entire original group that was synchronised from Google Workspace.

This kinda seems like I'm double handling users to add them to a group twice to onboard them, once to get them synchronised, and once to gain access to Confluence. Can somebody help?

Thanks,

Michael