Dynamic menu sub menu stays open

[DersJ]

Bug Report

1. Open a dynamic menu with multiple top level items, one of which has a sub-menu
2. Mouse over the item with the sub-menu, which will reveal the sub-menu
3. Mouse over the top level item without a sub-menu. The sub menu will stay open.

What is the expected behavior?

The sub menu will close when a different top level item is moused over.

Which version of Angular and Material, and which browser and OS does this issue affect?

Angular 9