I had this issue on my last two rides:
Mounting my new Edge800 and hitting "command-L" imported my activity in Ascent and displayed the ride correct in the map view.
BUT the total kilometers were short.
I imported the .fit file in GarminConnect and everything was displayed fine. I also did another test and imported the ride in trainingstagebuch.org, which also displayed the ride in a correct manner.
Here is the ride in trainingstagbuch.org:
(direct import of the fit-file by drag&drop)
Here in Garmin Connect:
And here you can download the fit file, which does not import correct in Ascent and the exported TCX from GarminConnect which imports fine then in Ascent:
Rob, please fix the direct import problem with .fit-files ASAP. Thank you!