TT Adventurer - swim distance doesn't work half way.

These past 4 days I noticed:
(1) the watch was working fine for the first 200 m or so but stuck at the same distance even after I have done extra 4-5 laps. A few laps later, it add up all the "missing" laps that I have done.
(2) Yesterday it stuck at 450 m and not moving an inch. Thought if I sync it would give the correct reading but nothing happens, still recorded as 450 m.
Comments
BTW I also noticed that the swimming distance "jammed" after I replaced with a new TT Spark strap, originally was using the Adventurer strap.
Photo attached - Adventurer strap (Orange colour) and TT Spark (Indigo Blue).
The watch face seemed to be raised by 2 mm above the mounting when using TT Spark. I am not sure whether this has caused the error/malfunction.
Will try with the Adventurer strap later today.
Superusers
I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question.
yes, I noticed the same erratic behaviour when I do this type of exercice... I fear this probably has to do with the way Tomtom algorithm for detecting laps works: it basically starts a new lap when it detects a u turn, so if you don't turn, it's a bit lost: sometimes it understands you swam 1 length and stopped (but timing will be wrong) sometimes it misses out completely (probably thinking that you were just shaking your arm for a little while, but not swimming...).
... my solution to solve the issue would be to swim at least 2 laps before stopping: the problem disappears when i swim normal sets.
also, you might want to try setting your watch so that it vibrates when it detects a turn : it helps a lot to know what makes the watch detect/miss a turn. you can do this in training>lap>distance>1 length
2) It works well when I set Swim-Distance-Goal.
3) Prior to this problem, when I looked back at my past 10 days swimming records, they were all correct ... puzzling.
Thank you. will try your methods. cheers..