New Altimeter algorithm not working, firmware is 20.30

I agree with Claes. If that's because I'm also in Sweden I don't know, but I doubt that. My back yard is at 130 m, but I can wake up in the morning and notice I've moved to 400 m, or to -20 m (not sure which is worst).

Calibrating before bedtime sometimes works, but not alway.

Hint to Brad Trenkle: The Fenix 3 was never this bad. Of course it could change when there were large weather changes, but not like this, for no apparent reason.

I think a lot of people misunderstand the fundamental physics of how an altimeter works.  If any weather is moving through one's area it is super easy for it to show a change of tens of meters. 

I'm a pilot and super acquainted with the variation that comes with altimeters due to ambient air-pressure changes - there's a reason ATC gives us nearby baro readings on each handoff.  When you are sitting in your house you would not want Garmin to power-on the GPS in an attempt to correct for baro drift (because it is unlikely that you'd even get sats, and this pointless attempt would burn power).  Which is why garmin does that only when you you first start a GPS based activity.

Yep, you are absolutely correct. 

This is a very old argument, which can be even right per se: the problem is that other systems, even Garmin systems like the old eTrex, are super steady and accurate in terms of altimetry, and weather does not affect them very much. 

This means that the problem can - and must - be solved.

Nope. The complaint (for everything everywhere) is old. Here is what Garmin (who knows better) says: "The barometric altimeter on Outdoor watches use barometric pressure to determine changes in elevation, as well as changes to the pressure caused by weather patterns. Outdoor watches will continually monitor barometric pressure to determine which mode is most appropriate at any given time. "

Then please go and find how the altimeter (barometric) in the eTrex works. You will find out that it work pretty much the same as the Suunto FusedAlti: a combination of barometer and GPS, with recursive mutual calibrations, that is much less prone to weather. For some strange reason, Fenix doesn't have this.

"rock solid" and wrong is still wrong. ;-).  If you want something that never changes while you are in your house, you don't want an altimeter (because altimeters are based on airpressure).

If I'm inside home, so much for GPS isn't it? Apparently, everywatch around is better than a Fenix or even a Garmin...go figure why they sell so much of this bad stuff...

Strange, my "altimeter" watch worked before Garmin introduced the latest change in the software.
Despite numerous complaints on how it worked out in the betas, they decided to push out the change anyway.
This affected my watch (and others too), and I am trying to find out how other people managed to get it to work. Your comments are not helping.