No calculated demurrage or despatch in P&L - only agreed costs

In the VC in we record demurrage and despatch rate for both load and discharge.
In the laytime calculation the Demurrage or Despatch amount are automatically calculated, but we record the agreed Demurrage or Despatch and this value is what we expect to see in P&L.
We have noticed that, as in below case, if for ex the system calculates a despatch and we instead record an agreed demurrage (and therefore put the agreed demurrage value and 0 in the agreed despatch field) P&L shows both Agreed Demurrage AND calculated despatch amount. We need instead to only see Agreed Demurrage and Despatch.