Thank you for posting your inquiry here in Microsoft Community, coldwave100.
I'm sorry to hear that the display doesn't automatically rotate. I'll do my best to assist.
Is the keyboard connected when you test the auto rotation of the screen display? Does the Rotation Lock gets greyed out when the keyboard is connected?
Try to remove/detach the keyboard and if you have enabled the Rotation Lock before, please make sure to disable it. After removing the keyboard, try to check if auto rotation works.
Let me know how this goes by replying on this thread so I can further assist just in case.