iPhoneXS Battery Activity Graph Mystery
 

Bedtime Monday night I put my iPhoneXS on charge, unplugged it the next morning. Normally I would not expect to have to put it on charge again for at least two days (my usage is very light). Very surprised this morning (Wed) to see it was down to 16%. Recharged it and whilst doing so looked in Settings / Battery at the battery level and activity graphs. The activity graph showed light blue bars at max height, with dark blue bars just showing at the bottom. Looking at the 'last 10 day' graph, it was only since Monday that these chart-topping light blue bars appeared. Have no recollection of doing anything unusual with the phone activity-wise over this period. Has it been hijacked?! :uhoh:

Anyone any ideas?

Graphs of activity:-

https://cimg6.ibsrv.net/gimg/pprune....80ffe61864.jpg
https://cimg9.ibsrv.net/gimg/pprune....c8e856a261.jpg

Managed to have an on-line 'chat' session with Apple Support last night. Diagnostics were run, nothing amiss found. All I gleaned is that the light-blue bars represent activity while the screen is off (!). Which means my phone spent a continuous 48 hours doing something - the question is what?! The 'Battery Usage by App' list did not show anything untoward. Mystified and somewhat worried...

I would guess that the ‘battery usage by app’ list might provide a clue, but you mentioned that it did not. Is there a chance that iOS performed updates in the background? It could be some bad programming within an app that caused this. Keeping everything updated and offloading rarely used apps might prevent a reoccurrence.

edit: that currency app is at the top of the list on both screenshots, you could remove that for a while and see if the situation improves.

Thanks. I had the same thought re the currency app and deleted it as well as a weather app, thinking it might be running in the background - although tapping individual bars on the graph (which gives app activity) did not show anything untoward. Also rebooted the phone. Since then only dark blue bars appear in the graphs - which is a relief although I still would really like to know for sure what on earth was running in the background (screen off) all that time.