Have the copy & paste controls in Numbers changed recently?

Okay, it's been nearly a year since I've used Numbers but something I used to do routinely doesn't seem to work any more.

Before, I would use the key-commands "command-alt-C" & "command-alt-V" to copy a formatted style from one cell to another. So, for example, as I checked each transaction against, say, a bank statement, I could pick up a cell with the different background colour & paste it into the cell that was checked & it would change colour.

Sometimes I had cells where a number of things had changed & I could copy & paste this cell style to another cell in one hit, without having to go & find all the different changes & do them individually.

So far, so good.

What seems to have changed is that I now can't seem to pick up the formatting of an empty cell & paste it into a formatted one.

Take the example in this screenshot.

What I would've done here is used the key-command "alt-up arrow" to duplicate the row upwards.

But the new row was a debit, not a credit, so I would very quickly "command-alt-C" a pink cell, "command-alt-V" to paste in into the next column (where £174.45 is) & then repeat the process on a white unformatted cell to fill in the now blank pink cell.

But the unformatted cell is not copying. Or rather, nothing pastes when I use the key-commands.

So has something changed? Is the white cell, being the basic cell of the table I created before I did anything to it, technically "unformatted" so there's nothing to copy?