It's a shame that the activities already stored on Garmin Connect with a sub-activity are imported into the Android app with a dot "other" activity class and not with the parent category (Running or Cycling for example).
And if I change an activity in the android application by assigning eg "running", then it will also change the type of activity on Garmin Connect by deleting sub-activity ...
In short, it is not possible to maintain a sub-activity in Garmin Connect and have the parent category in the Android application ! This is very disappointing.