Downloaded a tcx file from all trails and imported the course - The Course points in the tcx files do not get imported.
I didn't check Import, but Exported TCXs from Connect are without points/laps. To save them, you need to download FIT and convert it on your own.
So, if you imported some TCX with points included, then probably Import discards them the same as Export does. Maybe try converting it to FIT.
And yes, would be better if Export/Import include also points/laps for TCX.