With the latest update to Illustrator 27.2, I've found the "Navigate to Next Document" keyboard shortcut to have stopped working. I have checked the Keyboard Shortcuts tool and verified that it remains as "Illustrator Defaults" and it is set to ⌘`. In fact none of the related shortcuts work.

To be sure, I've tried a different keyboard with the same result and the shortcut does continue to work in other applications (as it is the default shortcut on macOS to cycle around documents.)

macOS 13.1
MacBoook Air (M1, 2020)