I'm training with Coach Greg for "Garmin Coach Half Marathon Plan" and my VA4 recently started to record and display inconsistent pace (even during workouts), but GPS track is OK. What can be the cause?
Today, for example, I needed to run 20 min at "goal pace". I did it, but it was very hard to keep a consistent pace because my watch showed wrong values as you can see from the image.
Software version: 5.80