I'm pretty new to the whole Apple story, so i'm not sure if this is possible at all.
The story is that we have unsupervised corporate-owned iPhones at work. Now we are about to enroll an MDM (specific MobileIron) and the devices need to be in supervised mode.
What we tried so far:
Backup the iPhone (iTunes), supervise the device in Apple configurator 2, and push the backup back onto the iPhone. Somehow my Instructor managed to get it working: the iPhone was now supervised containing all user data. New day, new iPhone, he did all the same steps again (iTunes and iCloud Backup), an reproductibly we couldn't get the backup back to supervised mode. We've tried it with 3 iPhones 5s and on one iPad mini 2, it was either wiped and supervised, or it was only the unsupervised user backup.
I've been searching https://discussions.apple.com and other boards since last friday, no success so far. What i found were instructions for new, wiped devices, which didn't help.
My last hope is that you can help me solving this problem.
Is it possible to supervise a device without wiping it and restoring or keeping the users data for it?