Thank you for your asking. I came up some home troubleshooting tips below for you to try on
1. Enter "Safe Mode" and leave a 80%-100% phone in sleep(idle) mode in a night, and provide me the screenshot of
②Setting>Battery>3 dots on the top"Show app usage"
# How to enter and exit "Safe Mode"https://www.asus.com/support/FAQ/1005163/
If the battery works well in "Safe Mode", please check on any disturbance from the installed 3rd party Apps.
2. If the issue remain the same in "Safe Mode", please try "the Factory Reset"
Settings>System>Reset options>Factory data reset
Please note that once the Factory Reset is completed, all data, apps, settings and personal information will be deleted.
3. How old is your battery?