interval trainings using garmin swim are correctly recorded, transferred and displayed in table views of GarminConnect
BUT
graphs do not show the right length of intervals and pauses
Looking deeper into SVG sources shows a suspicious behaviour on right shoulders of all bars
looks like svg path used here only draws every 2nd line caused by a missing "L" in front of every other XY pair
svg snippet : <path d="M 8.27450980392157 206.26428700541877 L 27.080213903743317 206.26428700541877 27.080213903743317 206.26428700541877 L 45.88591800356507 206.26428700541877 45.88591800356507 -120 L 64.69162210338682 -120 64.69162210338682 179.401205298746 L 83.49732620320 .........
A fix for this problems would improve happiness and satisfaction with this Garmin product :-)
P.S.
hint for highcharts - container: (SVG specific) you can reduce the CO2 footprint and size by using horizontal and vertical plot movements (H+V instead of L ) for rectangular bargraphs, in blocks relative plotter (h+v) movements and decimal digit truncation also could save bandwidth