Hi guys,
since updating the watch to version 20.26, the elevation and temperature are displayed the same and there is no change

I have the same issue. Along with activities showing no elevation (and incorrect temperature), even if the "elevation correction" is used, this only updates the activity.
The Hill score, Floors climbed and any challenges that are elevation/floors related are all effected.
I use Garmin Coach Daily Suggested Workouts as I have been overtraining.
I have updated to 20:29 and plugged into laptop and updated maps but still no improvement for over 2 weeks now.