Highly inacurrate beginning run speed

Looks like what happened to me. link

Hmm, seemed to be a one time fluke in your case. For me, it's been happening for months through multiple updates :/ 

TL;DR the green GPS ring is a lie, wait for pace to settle to 0:00 before pressing start.

Yeah this has been a general problem with Garmins for years, ever since they improved the time to get a GPS lock from minutes to seconds. If you look at the GPS track in the situations you described, I bet the first part of the track is a squiggly line (as opposed to the straight line you probably ran in real life.)

The problem is that when the GPS ring is green, you don’t necessarily have a lock yet. If you stand still and look at your pace before actually starting the activity, you’ll see that the pace is constantly changing (cycling through crazy high speeds, like you described.)

What I always do before pressing the start button is wait for the green GPS ring and wait for the pace to settle to 0:00. It can take anywhere from 30 seconds to a couple of minutes for me, but if I don’t do it, the beginning of my run will be messed up, like you described.

I'll definitely give your method a try, I suspected I might have been launching it too quickly, I never noticed the pace change before pressing start, I'll focus on that.

Thanks man

That is interesting. I always start directly when it hits green. Never had a problem besides that one occasion. Maybe I have good GPS coverage here, so an instant lock? I hope this solution works out for TS