Not sure I understand the title of this discussion; but I can't think of any reason why the Business P&L should "agree" with the Rental Property P&L.
Reports found at Reports > Business will only use "business transactions". A "business transaction" must have either a Schedule C tax line item assigned; or have NO tax line item assigned and have a "Business Tag" assigned. Business tags are created at Business > Manage Business Information > Add.
Reports found at Reports > Rental Property will only use "rental property transactions". A "rental property transaction" must have either a Schedule E tax line item assigned; or have NO tax line item assigned and have a "Rental Property" tag assigned. Rental Property tags are created at Rental Property Rent Center > Properties & Tenants > Add property.