When I load in a SimBrief flightplan, it appears as if PMDG completely ignores the CI and payload values I have set up. For example. In my simbrief flightplan I have stated a cost index of 30. PMDG changes this to 18.
No, this isn’t really a bug. The CI value isn’t imported via the flight plan. 18 is the default value which you can change via the plane’s parameters in the FMC.