1. Open a Menu (e.g. the first Select at https://doc.wikimedia.org/codex/main/components/select.html )
2. Select the second item. The Menu closes
3. Click on the Select again, the Menu opens
4. Press the down arrow

I expect: the third item (the one below the selected one) is highlighted

What happens: the first item is highlighted, regardless of which item is selected

However, if at step 3 you open the menu with the keyboard instead (by pressing Enter or down arrow), it does behave correctly. It also behaves correctly if you click away to blur the menu, then focus it again by navigating to it with the Tab key, and then open it with Enter or down arrow.