Inputting Notes using "Y" on the keyboard

I have seen John enter notes in percussion staves by selecting a duration and pressing “Y”.
The documentation also says this should work.
When I try - nada! As in absolutely nothing happens. Is there some key setting, option or command I am missing?
Note input via mouse works just fine.
No one else has reported a similar issue so I assume it must be my setup. MacOS 10.13.6

Have you possibly overridden any of your shortcuts and set Y to do something else?

You could try quitting Dorico, then going to /Users/your-username/Library/Application Support/Steinberg/Dorico 2 and finding the file keycommands_en.json, then change its name to e.g. keycommands_en.bak so that Dorico won’t load it any more. Then try running Dorico again, and see if the default Y shortcut now works.

Doing as you suggest and renaming the keycommands_en.jso to bak works - suggesting that I had overridden it at some point. However, I don’t remember ever doing so (or having the need to do so!). For now I will accept that it works and leave it as a frozen mystery unless the behaviour recurrs.
Thanks for your quick reply and help.