Bins in the Project Panel no longer save the "open" state. When a project is closed and re-opened, all the bins are automatically all closed. This makes large projects very difficult to come back to, or collaborate on with others.

This is a new bug, and was introduced a few versions ago. Not sure which version was the culprit, but it's been since at least 15.2

Windows 10.0.19042
Premiere 15.4.1