Call History Keeps Downloading.... From Where?

On another forum, a user mentioned that this issue is possibly related to my carrier. So I called AT&T and of course the rep did not know much and opened a case report to investigate. Has no one out there noticed this on their devices?

My entire call history logs come down, at least 6 months worth. When I delete each entry individually, another entry appears. This is not from FaceTime at all, that is disabled as well. I mainly do restores to re-calibrate the battery and because there are hiccups within iOS that seem to be resolved with a restore, although other hiccups are brought to light.

Any thoughts on where months, possibly years, worth of call history comes from? It's not KeyChain or iCloud Backups.

I would say the original iPhone had software with better stability then the iPhones of today, because they had less features. My wife and I both have the 5s running 8.4.1 on AT&T. I can tell you our phones act differently when it comes to stock applications and daily use.

One example is that on the camera editing feature; I can fix my photos and send them to OneDrive/DropBox and edits are removed. My wife can edit her photos and send them to my OneDrive/DropBox and edits remain. Odd!

I can also tell you that her call history does NOT sync down when a restore happens to be done to her 5s, even though our devices are setup the exact same way for syncing purposes such contacts, notes, reminders, etc...

Somebody has to know where the call history syncs, just like "recents" when typing an email. I send to an email address one time, but it remains in the list after a restore. And no, the "recent" is NOT in my contact list.

So I did another restore for testing purposes and have concluded that call history in stored within KeyChain. I restored my device and kept KeyChain off for 1 1/2 days, no older history appeared (picture 1). I then enabled KeyChain and within 4 hours (same as before) I was alerted with missed calls from months back and call history reappeared (picture 2). If you look at picture 3, you can see how the dates are so sporadic, skipping days and weeks. It goes from yesterday to November 12, 2015.

After all this, I "cleared" all call history and disabled KeyChain. I waited a few hours and a few restarts and re-enabled KeyChain. So far it's been 6 hours without call history returning.

So I RESTORED AS NEW my 5s again yesterday morning and set it up how I normally would (disabling iCloud backup and enabling KeyChain) and no call history has appeared as of now. It has been over 24 hours and if it would happen, it usually happened around the 4 hour mark.

At this point, I think it's safe to assume that KeyChain was the culprit. Even though KeyChain states it saves Passwords and Credit Cards, it also saves a WiFi SSID/Password connection history. With that said, I believe what I did (noted above) fixed this issue with call history. I will update if anything changes.