Hard reset (how to)

How to do a hard reset that lets the watch forget everything?

As of today Fenix 6x pro can not get a GPS fix. I tried all sorts of resets to get the watch as fresh as possible and start all over again. The watch seems to find old data that is somewhere stored apparendly (like vo2 max, step goal).

How to do a complete reset?

(Tried all ready through the menus and with the buttons...)