This article explains how you can change the user on an iOS device. As if you don't go through all the necessary steps you might find that the installed apps and configurations don’t match your expectations.

1. Wipe the device. This will also remove previous user data, and make sure there are no old settings causing issues. You can see the step-by-step instructions in the Remotely wiping a device article.
2. Change the user in GoTo Resolve MDM. You can do so by navigating to Company > Users on your GoTo Resolve MDM site and either using an existing account or creating a new one. Go to Management > Devices and double-click to open the device. Select Settings tab > Edit then select the new user from the drop-down list and select Save.
   
3. Re-enroll the device directly to the new user. Please see the Manual iOS device enrollment (or alternative Enrollment instructions for iOS device users).