EPS Will Not Load for External User

P6 EPPM, Version 18

Our organization has added an external business partner to P6 EPPM. He can log in and see the tabs that indicate to which modules he has access. The EPS structure to which he has been granted edit access will not load.

An internal team member who has the same access to the EPS structure, can see the EPS, is able to import schedule data, and can open the schedule to then view activities from the Activities tab. The external user is somehow able to see these activities when he clicks on the Activities tab.

Please advise.