Genera System Services Excessive Data Usage

It’s been two weeks since I last reset my mobile data usage statistics, and I’ve already racked up over 3 GB of general system mobile data service usage. Additionally, my software updates have used up half a gigabyte, even though I have all software updates turned off for both my iPhone and Apple Watch. This problem of excessive data usage, especially in the general category (I don’t even know what this covers!) has continued for nearly a year now, and continued occurring, even when I switched countries and SIM cards twice. Even when I turn mobile data off and only switch on when I use it, I still use over a gigabyte of data every couple of weeks. This is ridiculous as when I checked my friend’s phone, they’d only used 11.6 MB over five weeks. This is obviously very annoying, and quickly uses up my data plan. I have most background app refreshes off, low data mode on, and analytics and most location services are off too. There isn’t anything happening that should use this much data. The not very useful answer I got from Apple was to reset my whole phone, which I really don’t want to do. Is there anyone else experiencing this, and is there any way to reduce, or prevent this from happening? Thanks.!