Intune MDM corporate accounts mobile data usage

We have recently completed our rolled out of iPhone using Intune and ABM for corporate enrolled devices. We have been made aware of some users exceeding their mobile data allowance. Looking at the mobile data usage on the device this is being consumed by System Services and within this "Corporate Accounts".

After some testing this appears to be when apps that are being pushed or updated whilst on mobile data. If on WIFI this updates as normal, but if no WIFI is available it appears to update using mobile data as soon as the app is available.

Has anyone else seen this high usage for "Corporate Accounts". Is there a way to restrict the update and initial push so they are only downloaded whilst on WIFI? The app store is hidden for the end users with apps being set as required in Intune. Under General, App store mobile data was turned off but was still using mobile data.

A policy is in place to update as soon as available to remain up to date but we would like this only to happen on WIFI.

Another issue was a single 172mb app was pushed whilst on mobile data but was recorded as using 620mb of data on "Corporate Accounts"

This is for devices on IOS 16.6, using company portal for enrollment.