Data Usage from "Deleted Accout"

[sas300]

Hi there,
I own a Lumia 650 for about a month and have a problem with high data usage. Last month it ate through my 2 GB mobile plan. :angryata usage in System shows "deleted account" and "system" as big users. I had to change the email-address from my microsoft account - perhaps thats the culprit?

I already did a hard reset, turned off auto backups and message sync...

Any suggestions highly appreciated!
thx sas

PS current my firmware is: 01078.00037.16082.41002

 

[Sentient Golf Ball]

I've just noticed a "Deleted account" entry as well. Did you ever work out what it was/is?