Garmin 5S - Distance accuracy

Hello Guys,
I have been using the device for over 7 months and I have a question regarding how accurate is the device when tracking KM/miles.
So essentially I have been running the same lap over and over again and I can see a difference of 1 km sometimes.
Essentially, if I run slowly it measures 10.5 km , if I run faster is shows 9.5 km .
Is this supposed to be like this? If that is the case , the device is using the acceloremeter to calculate the distance and not the GPS,isn't it ? So this will never be accurate.I thought it had the GPS ??

0 antra_s over 6 years ago

Hi, people

I have been using Garmin Fenix 5s now for a little bit more than one year.
Over this period of time I usually run the same routes and all the time until now the 1km marks were +/- at the same place.
But now - since 8 Mar, 2019 my watch has been measuring the distance very very incorrectly.
Over 10km distance I get approx 300-400m less than it used to calculate all the 365 days back. I would understand if I got more (losing satellites etc.), but getting less - and much less.. So the pace for every 1km is so wrong and so slow..
Does anyone know what is the problem and how to solve it?
I tried changing data measurements from Smart to Every Second, but it doesn`t really help. I haven`t changed any sports settings (3D Distance/ Time or GPS, but currently both 3Ds are OFF and Satellites are GPS only).
Can anyone please help or has had a similar experience, or any suggestions how to solve it?