At times yo0u can see version 0.00 for GPS if a new version was installed, but it's yet to have GPS used. When You tried to get a GPS fix, how long did you wait? In "about", if you go to the last page, what does it say for EPO?
I waited for about one hour.... That's when I gave up. But I just did a 25 sec on light restart and suddenly GPS: 2.10 appeared. Finally got my GPS fix.
Thank you for posting your solution here. I had the same problem with my new Fenix ??5 Plus after the first update with Garmin Express (GPS 0.00). All attempts to fix the bug were unsuccessful, update to beta 3.55, downgrade to 3.10 and reset the Fenix. But your tip worked! Now I have GPS reception again and the version GPS 2.20 :) Thanks!