When you power on the Kodiak the G1000nxi will go through a start up. You need to wait for that to complete before attempting to enter a flight plan on the MFD screen.
As this is more likely to do with the G1000nxi and not the Kodiak, probably better to ask your question here: https://forums.flightsimulator.com/t/garmin-g1000-nxi-issues-and-support/549927?u=alpineb4652