Apps not deleting (MOSYLE MDM)

Here at this school I work at, we have the free version of Mosyle.

I am getting the following error when I try to remove apps.

Uninstall Not Allowed

This app cannot be deleted because it is required by XXXX Primary School       

This is happening on student owned iPads that enrol their devices to Mosyle.

Their is no restriction set anywhere that I can see. Only for supervised (school owned devices)

The weird thing is, this will happen to some apps and not other.

Not sure if this is just a Mosyle issue, or whether it affects Jamf and intune as well.

Some further findings:

Further findings with this. 

If the app is added via the Mosyle 'Manager' on the iPad itself, it will not delete, again not all apps are doing this. 

This is happening on managed and supervised.

IF... I do the above on a supervised iPad, it will not delete. I will get that message.

IF... I send the app to the supervised app via Mosyle, not the manager app, I am able to delete the app without the message.

I have narrowed this down to a problem with the manager app and installing apps via the app on the iPad. 

Thank you,