Track Run "New Feature" - Garmin Should Round Distance

have you checked to see if the track run activity doesn't already do that: https://www8.garmin.com/manuals/webhelp/GUID-E5C62F3F-DCE3-4197-8CA5-E419B2A55D12/EN-US/GUID-6F710D25-D03C-4C65-A42D-79475153F77E.html

It does not. See below track run activity from today. V8.37

what are the 40/50m distances in between the laps?

I wonder if that is throwing off the calibration.

Those were "rest" laps. I was just walking around next to the starting line. I did a separate continuous calibration run just before, so shouldn't be affected. The map actually looks spot on. It's just the paces are not calculated based on the "most probable distance". 

I suspect it was these that were preventing calibration from working. The way I read it, it recalibrates each time, so a prior calibration wouldn't work, and as it didn't have 3 laps in a row it was unable to calibrate.

My understanding is different, the watch only calibrates once. It learns the track and save that for future runs. It would be “strange” if the watch required calibration every time. Lots of people warm up outside the track or in outside lanes.  

I am curious. Did you see any alert (like pace, or performance condition) or did you look at any glance during the laps that end up short?

@stepanect:

you are correct - it can store up to 10, however you have to calibrate it first before it can work, and no you can't warm up/cool down using track run unless you are running laps doing that, otherwise it mucks up the calibration - like I stated above.

The reason the laps aren't accurate is because you haven't allowed the watch to calibrate for the track (unless you have done that previously - 4 complete laps in a row without stopping?.

See attached link which explains the whole process in detail, including how to use your watch for warm up/cool down if not running around the track:

https://support.garmin.com/en-GB/?faq=eH8V1VwjN338uo8C5PgDJ7

(ps - use Change Sport hotkey to create multi-sport run/track run/run option - quickest and easiest way).