You will have to select multiple lines.
I did select multiple lines and it still does not work. I know it used to work.
So I installed EMeditor on another computer and the tab worked. Then I exportedimported my settings from the one that does not work into the new one and it also stopped working.
Would you please email me at email@example.com with the exported settings after zipped? I will try to reproduce your issue. Thank you.