After updating Fenix 6 Sapphire to 12.20 problems with bluetooth, wifi, ant+, freezing, battery drain

I had a fully working Garmin 6 Sapphire until I updated from 11.75 beta to 12.20

Now I can not sync with my mobile, the wifi no longer works, the HRM and Tempe does not connect. The battery drains empty in 1-1,5 days. And the watch freezes repeatedly.

Removal and reconnecting of sync to phone and sensors makes the Fenix connect for just a short while.

I have rebooted, downgraded to 11.75 and re-updated, reconnected. But my Fenix remains a catastrophy.

I have not had any problems with updates before, and always been puzzled my the variety of update related problems reported in this forum.

Now I have been hit by the ***. Happily my wife’s 6S works well after the same update from 11.75 to 12.20.

I will have to wait for a new update, as I do not have time for 3h of “support” from Garmin that leads to nothing for similar problems - as reported in this forum.