Recently my Venu 3 has, started reverting to showing a negative altitude when not recording an activity (I use the Glance watch face). Even if I reset it via GPS, or via the manual input, after around 10 minutes it changes to showing a negative number. Our house is bang on 85m alt - today it's showing - 48m. I just reset it, and a after a mins it's back at - 48 again. I've tried making sure all the ports etc are clear at the back.
I've emailed Garmin support twice but apart from an automatic reply there's never any answer from them.
Is it a problem with mine or does anyone else's do this as in the past it always seemed to nearly spot on all the time?