I was swimming on average 3 times a week in july-aug. Until the last day the local pool was open (on 31st Aug). In other words I haven't swam a meter since the 1st Sep!
However the endurance score shows over 20% contribution of swimming in the last 2 weeks (both totally in September, so I have not swam a second)
Garmin connect: 5.5 android, fr965 fw: 20.26 (upgraded from beta probably in the beginning of September)