Provider configured a role with the 'Billing Access' priviledge disabled (to disable/remove the PBA link at the top of the control panel) and assigned the role to a staff member.
When the staff member logs into the POA Provider Control Panel the link to switch to PBA is present in the POA Control Panel and the user can still switch to PBA when they should not be able to.
This is the problem known as POA-71569.
If you need to restrict access to PBA to Provider's staff members create appropriate role in PBA and assign it to required staff members in PBA. Users will be able to switch to PBA and their permissions will be restricted by their role in PBA.