Inaccurate gps tracking after update 12.23 on FR 955

Just to drop by and post that I don't see any GPS issue with my 955.

Currently I am on 13.22.

If GPS issue is not region specific, then this is most likely a HW issue.

To eliminate GPS region specific issue, I urge you to try on other region or country if possible.

Are you using smart record or every second data record?

I've done tests in very different parts of my country (Brazil). 

Like I said, for run and walk activities the problem is not so visible. Specially when using smart data recording. 

For other activities like water sports its terrible.

I would post some prints but image pasting is not working here. But I posted the same problem here with pictures, since the problem is also present on the Fenix7: 
(+) Inaccurate GPS tracking with latest firmwares. - Public Alpha 11.xx - Fenix 7 Family - Public Alpha Bug Reports - Garmin Forums

Mine is every second. All are running and some cycling. No swimming.

Russia apparently jammes the GPS signal: gpsjam.org/

I just confirmed my suspicious! The problem started after they changed GPS software version from 2.35. The problem started with GPS 2.37 for bot Fenix and Forerunner lines. But 2.42 didn't fix the problem.

I backdated the F7 firmware to stable 9.33 which uses GPS 2.35 and all tracks are smooth and straight again! 

Garmin, now I did your job on isolating the issue, please revert GPS software to 2.35 on latest firmwares until tou can fix the problem. If you don't want to do this for public release, at least make an Alpha version for us to download! 

Yesterday: F7 solar firmware 11.15 - GPS 2.42

Today: F7 solar firmware 9.33 - GPS 2.35

Both were using all systems + every second. 

One thing to notice is that the problem with Open Water distance measurement persists, even bigger diference
Measured 256m vs 360~370m on all others.

It's possible in the Fenix7 because they release Alpha firmwares for manual install. 
I don't see any alphas in 955 history so can't do the same.

Garmin has disabled this option - downgrade. Although it could show us if there was any bugs, errors in FW after 11.12…

But we will never know it.

I suspect we're seeing two different things here.

There is undoubtedly GPS jamming in evidence in the tracks recorded in Moscow. They're accurate until they pass close to certain landmarks, then become massively inaccurate.

Something different seems to be the problem for the Brazilian tracks (which is fixed by downgrading).

Pity our friends from Russia. I believe no FW change will ever fix this jamming.