System Services/Software Updates drawing lots of mobile data

Hello Sim-on87,

Thank you for reaching out in Apple Support Communities. You've done an excellent job on your end to help isolate this behavior. There's an extra step we recommend for you to perform which is to update your iPhone to iOS 16.5. This latest update was just released and can help provide software improvements that may help resolve this behavior. Prior to updating the software, we recommend to make sure that you have a recent backup of your data. Once the iPhone has been updated to iOS 16.5, please monitor the next 24 hours and see if the higher usage amount of cellular data continues to occur for System Services.

If needed, here's how to update your iPhone:

Update your iPhone or iPad wirelessly

1. Back up your device using iCloud or your computer.

2. Plug your device into power and connect to the internet with Wi-Fi.

3. Go to Settings > General, then tap Software Update.

4. If you see more than one software update option available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

Following these steps can help and is outlined in this article: Update your iPhone or iPad - Apple Support

We look forward to hearing back from you with an update.

Kind regards.

Hello Sim-on87,

Thanks for the followup. At this point, we suggest you contact Apple Support so that they can look into this with you further.

They can be reached here: Get Support

Take care!