This is not a "baro holes wet" situation. I stay in sunny SA, it is summer and the last time the unit saw a slight drizzle on a ride was shortly after New Year. And for the record, I got out late today, it was entirely clear the whole way, temp went up a bit but nothing serious. So nothing could have "fooled" the baro.
Rode a lot of singletrack lately and saw some elevation discrepancies, pressed correct elevation absent-mindedly with some eye popping results. But never thought too much of it. Today I rode gravel roads, so had time to look at the unit. Esp after almost at the top of my first hill, I saw my elevation gain field is still at 0m. Looked at the actual elevation field: 5m. Way off but whatever. Except when I looked at it again just before the top of the hill, it was at -2m! My unit was heading downhill while I was heading uphill.
It was an interesting ride ito observing elevation on the unit after that and I got so crazy that I stopped even watching it after a while. It was ridiculous. Actual elevation was gaining when I was irl going downhill. Early in the ride, actual elevation went from -5 to 45 and my accumulated elevation changed only to 3m. I had a numerous k's gradual climb later in the ride during which the unit lost 150m elevation from where it started the climb.
I'm going to drop it in rice to maybe clear any residual wetness from a month ago. Not that after a very hot month with 45+ days incl that should be a factor. But what else can I do? At this stage I suspect it's firmware related, but see nobody else having posted similar experiences recently. Latest firmware, btw.
Any other ideas will be appreciated.
