Start with tightening the lower chassis screws to see if the issue goes away, although it can also be loose inside the LCD assembly, this procedure is a lot more invasive. I’ve also noticed it’s usually the lower chassis screws anyway, so the more invasive procedure is often not going to fix the problem. Refer to this guide to get to the screws for the hinges.
If you continue to have issues, then you need to try tightening the hinge screws under the LCD. To do this, you will need a plastic pry tool (and patience) to get the bezel off to access the screws.
If neither of these help, then the hinges are worn out or the plastic failed. These Chromebooks usually use fatigue prone plastic, even on the education certified models. The only difference between a consumer/business one seems to be the included contract unless it’s a little tougher at most.