In addition to the erase all settings problem below, there is one more problem after updating ios15. In the profile and App settings, 'app removal' is set to be disable, but the remove app operates on the device.
Of course, the app is not deleted exactly. Like Windows' shortcut icon, the app is deleted from the home screen, but it remains in the app library and can be executed. If the app disappears from the home screen due to some users' mistake, the user may not be able to find the app.
Is this a problem with iOS? Or is it a matter of SM?
Have you tried creating a iOS restriction profile? I am assuming that you are using DEP enrolled devices. There is a setting that prevents users from removing apps. You can also allow or not allow certain apps.
To create a profile go to: Systems Manager > Settings > + add profile.
Edit: make sure you have your MDM network selected first.
So this, to my knowledge, is expected functionality. Home Screen Layout settings are not the same as App Removal settings, as it appears you've discovered. This is important for a number of use-cases, such as allowing personalized layouts while still forcing the presence of applications for troubleshooting or other reasons (e.g. I want every device to have TeamViewer QS installed but don't care if folks keep it on their home-screen since I can instruct them to swipe until they reach the app library view and search for it)