It seems up/down now work but they behave unintuitively (see below).

Page up/down doesn't work and still applies to the page, which makes it hard to scroll through the list with the keyboard.

Left/right also don't work, even though it seems like they should because it's displayed as a grid, not a list.

Using up/down causes the list to jump about and switch columns, e.g. the following three screenshots show three sequential entries when pressing down:

The first two behave as expected, the dialog scrolls down one row, the selection moves down one row. The third one, however, is confusing. It has suddenly jumped to another position in another column, you can't see the entry you were previously on and it's not immediately clear what is happening.