https://forums.garmin.com/developer/connect-iq/f/discussion/1148/exit-an-application
You can not exit a widget with the popView or exit() call.
Unless your app has a background service, nothing should be left running or using battery in your app itself.
What you may want to look at is if sensors/GPS is left running when your app exits. For example, if GPS is left on after your app exits, that will consume a whole bunch of battery.
I've not ever seen this myself, but even if your app doesn't enable GPS, maybe the FW itself is doing that, and then not shutting down GPS when you end.
Is this being reported on a specific device/firmware version? Is it all f7's /variants for example? Only APAC devices? It sounds like a FW bug to me.