Same exact problem here. Happened when we upgraded to iOS 18 -> no new strange apps installed. All of a sudden System Services -> General, which hadn't even shown up in the top ten use cases before, is suddenly responsible for 80% of our monthly usage! The jump was drastic - my whole family easily shared a 10GB/month plan, and now even I can't fit in 10GB - and that's with not using my phone.
Did I mention this is with sending 95% of the time on WiFi, having all apps shut off from cellular use, and using low data mode?
The ONLY way to stop it is to turn cellular data off. But aspects of the phone literally can't function right over just WiFi, and this isn't why I have a phone.
Does anyone know what falls into this "general" category of apps? This problem has affected some folks since back in iOS 13.
Of course upgraded to the latest iOS - still no change. General uses up about a half gigabyte an hour even with the phone closed in my pocket and no apps running. I'm now faced with either paying for an unlimited plan - just because of an Apple Bug - or giving up my iPhone. This is crazy.
Like everyone else troubleshooting this problem, I've checked everything. No Wifi assist, etc. And it doesn't matter if you shut down individual app's access to cell use, or even individual system services, because none of those matter compared to System Services/general, which I haven't found a way to turn off.
Obviously this isn't affecting a LOT of users, else Apple would have to address it.
If there's anyone reading this who worked at Apple and can say what General means and where it comes from, that alone would be such useful information. Could this actually be a virus that operates through System Services?