Paste special How to activate ok button Ubuntu 20.04

Paste special’s ok button should be accessible by Alt O on the keyboard. If I click on the ok option with the mouse, Ok is actioned, but not if I use keyboard shortcuts. I suspect it is due to “return” in customise - keyboard - return not having any action attached to it. Is it relevant that hitting the enter key in a spreadsheet does not cause the cursor to go down one cell? Nothing happens.

What LibreOffice version, UI language and platform anyway? Might be there are two or more o mnemonics in your language in that dialog that are just cycled through and you’d have to confirm the OK button with Enter when active.

Ubuntu 20.04
Libreoffice 6.4.7.2
English

Cycling through more than one option for the same keystroke: This does not appear to be happening.

Any further suggestions?

Well, in 6.4.7 English-US I have Objects and OK in that dialog with O mnemonic.

Same question cross posted on the AOO forum

If you cross post, please let us know that you have done so, otherwise it leads to several discussions and a waste of time because several identical answers may be posted by different users.

When I type O or Ctrl O in paste special nothing happens. Hence the problem.

Have I made progress?

If I switch key bindings to Openoffice.org legacy, and then try Paste special:

ALT O O (cursor goes first to objects, then OK box and highlights the edge of the ok box in red, but the OK button is not activated)

What is the shortcut to send the enter key at that point?

Looking at Customise, Return is there as a shortcut key, but there is no value or description attaching to it.

Of course not, because it’s Alt+O, the legacy key binding is irrelevant there.

ALT O also does not prompt the OK button to work.

Looking at Customise, Shortcut keys, ALT+O has not been set up in calc. The Modify button is greyed out. Sorry to repeat my earlier observation but I do not have an idea how to reactivate ALT+O