User wants to create a vendor bill with line items for two projects. However, when entering the line items for the vendor in the Vendor Bills screen, it only shows the parent project and not the sub-projects (phases).
This can happen if the sub-projects (phases) have project assignments applied with only employees and no vendors. So if both sub-projects have an employee or employee group assigned to them, Core will not show up any vendors. If you add the vendors or vendor group to both phases, the issue will be resolved. Or you can have the phases with no restrictions at all by removing any assignments.