I’m using the GPSMAP 66s for 1 1/2 years now and experienced problems with (total) ascent and descent since the beginning. Some had been fixed a while ago, but on persisted. I contacted my local (German) Garmin support, but they told me they couldn’t see any failure.
The 66s is mounted with the Garmin Backpack Tether. While Hiking I’m watching the map often. Every time I grab (and of course press some buttons) the device the current height peaks up, drops and then levels out to the correct height. This causes a logged (in FIT and GPX) ascent and descent of +-10 Meters every time. On long hikes this results in exaggerated ascents. I attached a screenshot from BaseCamp from a short walk.
A year ago, Garmin offered an exchange of goodwill, but as I’m frequently using the device, I didn’t send it in for bad chances and lack a device for an unknown time.
I’m interested if someone can confirm this behaviour?
