Hi @TMwd,
The fact that you’re saying “the external user is the primary of team EAST” suggests that these users have an additional team – do they? If so, team-permissions apply to additional teams the same way they do for the primary team. This can effectively lead to these users seeing everything.
Generally, here’s the expected behavior: If I am a user who has team-only view permissions, then I can see all the records I own or the records owned by users with whom I am in a primary or an additional team.
Records cannot be owned by teams, only by users.
Best regards