CJ4 adding waypoints to LNM Plan

I created a flightplan in LNM and loaded it into FS20 at the World Map. The LNM plan had no departure procedures. When I took off and went to Nav/FMS mode, the plane started turning, but not in the direction of the flightpath in LNM. I checked the FMS and it had inserted a few waypoints, as if creating a SID that had not been imported from LNM. After these few waypoints, the plane followed the LNM plan to the end.
Why?

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