I've experimented with the various ways to import a Komoot course on a Garmin device and their effect on the turn by turn navigation function.
- The gpx file you can download from the Komoot website does not contain any navigation information, so turn by turn navigation doesn't work
- Importing this gpx file manually in Garmin Connect creates a course with a higher number of points (i think this is caused by Connect adapting the track to the known paths for a given activity) and creates navigation points, so turn by turn navigation works (but it's not the one you see on the Komoot website, which is based on real world roads geometry)
- Importing a course from the CIQ Komoot app is the same as downloading the gpx file from the website and sending it to a device via usb, so there is no turn by turn navigation
- The course uploaded using the Connect-Komoot auto sync feature found in these websites contains even less points then the Komoot gpx file, but Connect creates the navigation points (altough they are different from the ones from point 2 given that the route has less points and that Connect creates the navigation instructions based on the route geometry and not on the real world roads structure), so turn by turn navigation works, but it is probably less detailed because the route is less detailed (and again it is not the great navigation you would find on the Komoot website/app)
In all cases, when exporting a course from Connect, the downloaded file will not contain any navigation instruction. This is because Connect creates navigation instructions only when syncing a course to a device.
Also currently the Vivoactive and Venu series of watches are the only ones which support the real Komoot navigation from the CIQ app (they don't use the native Garmin navigation).
So, to recap, if you like to have turn by turn navigation the CIQ app is useless (unless you own a Vivoactive or Venu watch, then it's the best you can get), the auto sync option on the websites is useful, but could be better and the best option is to download the gpx file from Komoot and import it on Connect.
These results are from 26/09/2022 and could change in the future if Garmin or Komoot decide to change the way things work.
I tested this on the .fit files by using https://www.fitfileviewer.com/: the track points are under the "record" section while the navigation instructions are under the "course_point" section. For the komoot .gpx file i just opened it as a text file and there was no navigation info to be found.
