I charged my watch to about 80% whilst showering yesterday and saw normal battery drain afterwards, including during a short walk.
During the evening I adjusted a few settings (mostly lap notifications) on the watch using the Android app.
A couple of hours later at bedtime I noticed that the battery had drained to about 65%.
I powered off the watch using the standard watch Power Off option then switched it back on again. Battery drain was then normal overnight.
Forerunner 955 Solar. Software version 18.22.
Graph from "Battery Graph" widget by Cheurch.
