Edit Cells on Horizontal range

Hello,

just looking for some help/info with "Edit Cells"

edit cells works fine for a vertically selected range, but when i try to edit a horizontal range the option is greyed out and trying worksheet menu option Edit > Edit Cells returns an error "Cannot edit cells in present configuration"

flipping the worksheet, so that series are along the top and time along the side, allows the same range of cells to be edited without issue.

I have been unable to find a setting to enable or disable, horizontal edits.

should it be possible to edit a horizontal range

thanks,