From 27th October, my iPhone started using a lot of Wi-Fi Bandwidth and I can't use the Wi-Fi for any other purposes. Things I checked:
Checked for WhatsApp chat backup, No.
Checked for Translate offline languages, No.
Checked for iCloud Backup, No.
iOS update, No the auto update is off. Currently using iOS 14.0.1. Since all bandwidth is used I can't update it manually, so I didn't try.
Auto App-Update, checked and it is already set to not auto update over Cellular and Wi-Fi.
After all these steps, the problem is still not solved. So I reset my iPhone deleting all data.
Then I restored all data from iTunes Backup and tried to download all apps and it took a huge time and lot of data because something is running in background. So I paused some of apps from downloading and then cancelled the download of these big apps like Apple Office Apps, Google Office Apps and MS Office Apps and GarageBand.
I had a lot of photos and some files in the Files app in On my iPhone part and not in iCloud Drive. My iCloud drive and iCloud backup is always turned off.
Then I deleted all my Apps to check if any app is doing it. First WhatsApp and then every other non-apple apps + Watch app and Translate app.
It didn't work.
On 3rd November, I deleted all the files in my On my iPhone in Files app and deleted all my photos.
Now the phone, despite having nothing, is still using all the Wi-Fi bandwidth.
There is no way to check the Wi-Fi usage from iPhone. But the battery information shows this data.
I have never tried with cellular data since I don't have a cellular plan and this king of data usage will cost a lot of money if cellular data is consumed.
Also, now randomly, the phone is getting disabled for 5 minutes, mostly when I press the power button or when I restart the iPhone.
This is not Jailbroken or anything.
Has anyone experienced the same issue or any advice for me to solve this problem?
I have now deleted the Contacts app and the Wi-Fi usage became zero. I restored my iTunes backup and deleted the Apple apps, but still the same problem of using a lot of Wi-Fi data exists.