Weirdly Specific Problem I Have With Chromebook 3100

I have a school managed Chromebook that had been repaired recently due to a burnt USB-C port. When they gave it back to me after repairs, I had noticed that the battery was disconnected. I opened it up and reconnected the battery. After that, I booted my Chromebook and found out that some restrictions had been lifted. I logged into my personal Google account to see if I could activate developer mode but I could not. (I needed developer mode to reinstall kiosk apps)

I have questions. Why is my chromebook in this odd state of managed and unmanaged? What caused this to happen? Why can’t I enter developer mode? How can I install kiosk apps if I am unable to enter developer mode?

Thank you.