Why does swimming give so few training load points?

Last week I swam a mile, doing 100 yrd intervals, and had an exercise load of 130,aerobic score of 3.2 (impacting tempo), and anaerobic score of 1.6.  

I can only assume (1) watch defective, (2) your settings for your profile (age, weight, max and min heart rate, etc) is incorrect, or (3) you swam very very easy--which after 1 hr 20 min, I doubt.  

https://connect.garmin.com/modern/activity/9799543891?share_unique_id=102

https://connect.garmin.com/modern/activity/9800053078?share_unique_id=105

56 minutes swimming 65 load 

30 minutes running 50 load

I'm not the fastest swimmer but this only gave 33 load points

may you share you workout link like this ? https://connect.garmin.com/modern/activity/9799543891?share_unique_id=102 is better to understand

connect.garmin.com/.../9757741386

I suppose you are young so the heart beat was very low .... my max heart beat is 160 so I was in the  Zone 3 while you were in the Zone 2

here is the different scoring for a similar workout