[BUG ? ] Calc - Filter by Color unavailable when the cell is empty

I have a column with a conditional formatting style - “good” when the cell is blank.
But if I try to filter by background color, the green background color option is not available in the libreoffice filter when the cell is blank.

Is this expected behavior or a bug?

see the image

sample file
test_backgroud_color.ods (9,4,KB)

The null length string in a cell and the empty cell are not equals.

And the CF applied background color is not a DATA.
You can not get the cellstyle applied by the CF - you can not get it even by a macro…


Thanks for the answer.
I’m using version portable.
When version with the correction path is available, I will test again.