Anyone with Venu 3S - How long is your battery life ?

Hi to everyone. 

My wifes Venu 3S is lasting max of 5 days if run to 0%. 
so normally charged around 20% it will be max 4 days.

This is in smartwatch mode only and no activities. 

Could any other 3S owner chime in and tell me if 10 days advertised is true or not ? I have contacted garmin and I’m about to post it back for repair or we will be pushing for refund if that’s not the case? 

AOD is OFF 

Brightness is set to Auto and Minimum

Screen timeout is Short 

Pulse OX on demand only 

Redshift and do not disturb at night 

No notifications on watch other than calls 

No activities at all consume 20% per day of battery 

with short walk activity it’s 25% 

Advertised as 10 days battery in smartwatch mode with AOD off 

anyone can chime in and give me his stats ? 

many thanks