OnlyOffice data filter drop down select list Keyboard shortcut

I’m trying to find out the keyboard shortcut that opens filter drop down select list in OnlyOffice editor. Did a search and was led to the official site that seems to list Alt+↓ as shortcut.

Tried it and it shows a text replacement list, as shown the the error when trying to bring filter data drop down on a numeric column with keyboard -

There are no choices for filling the cell.
Only text values from the column can be selected for replacement.

Using mouse and clicking of the column filter list works, but I’m trying to figure my way around in a keyboard. I’ve used MS Excel and LibreOffice before and faced no issues doing the same thing.

I’m puzzled and hoping someone in the community has ideas on what I’m doing wrong. Thanks.