Issue Summary

When creating a guest group for external collaboration, if an internal user is added to this group, it will make it to be considered both a guest and an internal group, which causes further issues like:

• It will be available to be sleected under both the Guests and Internal groups part of space permissions.
• Adding the group will put it under the Internal permission part of the space.
• The space will have the Shared with guests flag even though the group is added to the internal permissions.

Steps to Reproduce

1. As an administrator, create a group to be used as a guest one.
2. Under the Product access part, add this group on the Guests tab.
3. Add guests to this group and at least one "internal" user.

Expected Results

The group should be considered guest-only, blocking internal users to be added.

Actual Results

The internal user is added, causing further issues related to the permissions of the spaces.

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available