Build #IU-232.10227.8, built on November 8, 2023
Create package with several classes.
Diagram the package (diagrams > show diagrams > show classes)
Delete a class from the package.
Diagram tab becomes unresponsive. It can be selected but refuses to repaint, even if window is resized. tab cannot be closed through normal means. Some portions of tab will repaint on mouse over.
Other tabs can be opened and closed. Tab area becomes dirty if diagram tab is the currently selected tab when tabs are added/removed.
Workaround: restart IDEA; tab automatically closes.