Why does recalculation of burden cost result in supplier cost event?

We've been having a problem where some expenditures (originating in AP) don't have burden cost so we recalculate the burden cost and it generates a supplier cost event type for GL.   We don't use supplier costs, these transactions should go to into Miscellaneous Costs instead.  What happens then in Create Accounting these fail because there is no default supplier cost account setup.  This is only happening on these transactions where burden has been recalculated.  If it is not recalculated it goes through as Miscellaneous Costs.  One of the team thought the cost should be going to the GL from AP