battery discharge faster

Yes, this is a known problem with the 20.xx firmware and we've been complaining about it throughout the beta phase.

I also tend to think, that consumption in "Standby"/ Fitness tracker mode is higher with 20.xx than it was with 19.xx (Garmin Share, Wifi off, Flightmode while sleeping).

Consumption during activities (SatIQ, external HRM and sensors) seems normal, though.

Yes battery consumption in watch mode is definitely a lot higher with these latest firmware releases 

The full battery is 100%. The power-saving mode drops by 3% overnight. It only costs 1% before upgrading. Can the developer of garmin explain the reason?

Same here! Charged to 100% on Thursday, only one 1.5 hour run and I have 40% on Monday. Quite dissapointing.

I reset my watch. Configure the same settings as before and fully charge. It has been 24 hours since the power-saving mode. The current power is 97%. Consumed 3%. It seems to be the same as before. I don't know if it's because of the reset.

Wait until you have completed an activity...

Same issue here. Charged to 100% yesterday and now at 86% after a half hour GPS workout.

I just ran for an hour and the GPS is working on SatIQ. The battery has been depleted by 4% and there is still 93% left. Version 19.18 also consumes 4% of battery in one hour, which remains unchanged from before. Next, I need to check the battery consumption after 24 hours. If it is still around 3%, it indicates that upgrading to version 20.26 has a high battery consumption issue. Resetting the watch is effective.