I have recently purchased my Garmin Fenix 5s plus, I have noticed when I start a run my pace is all over the place. It can be 12:30 pace then a few seconds later 11:10 then after about 3 mins it settles down to the correct pace, but it always seems a slower pace even when i start fast in a race. I have tried the full mix of satellites and it is still doing it. My last watch was a 735xt and it was much more stable. Anyone else had similar issues. I have also tried a factory reset