Battery drains suddenly

Hi all,

I have a Fenix 5 for 4 months already, normal use, normal battery usage ( charged every two weeks ) and suddenly, the battery drains at least 40% in one day.
Tried to remove all non-garmin widgets and no change.
Reset to factory settings and used with basic setup - the same problem, charged fully last evening, I am at 60% with no activity done, just normal usage.

Has anyone had similar issues?
I have raised a call with Garmin Support, this should not be expected on a 4-month watch.