So ive had my vivoactive for some time, ive had my share of update related battery life issues :https://forums.garmin.com/sports-fitness/healthandwellness/f/vivoactive-3-3-music/150332/battery-life-after-update
About 1 wk ago I experienced a system freeze in the middle of the night requiring a reset, charge was very low so i plugged it in and have experienced the worst battery life to date now down to barely over 1 day. I have not had trouble in months with upwards of a week prior to last week. I'm on 7.4 and cant say for sure when i updated to this version since the only time i look if when i run into sudden battery related issues. My use case has not changed since ive been using my watch, primarily use for 24/7 HR tracking and almost all widgets turned off and nothing added from connect iq, watch face is a simple default picked to minimize battery drain.