I noticed this too.  Microsoft documentation ( https://support.microsoft.com/en-us/office/keyboard-shortcuts-for-access-70a673e4-4f7b-4300-b8e5-3320fa6606e2 ) now says these shortcuts "do not work under all conditions" (see picture below).  Don't know if this is a bug or a feature to them, but it looks like a bug to me.

The workaround is to disable Monaco editor in Access options -> current database.  Then you can press Ctrl-period to go from design, datasheet, to SQL view, but can't go further.  Press Ctrl-comma to go from SQL, datasheet, to design view, but can't go further.