18.04 – The new Terminator tab is not displayed in the title bar

According to the manual, opening a new tab in Terminator is Ctrl + Shift + T. but where is the old tab going?

here is my tab 1 and i've opened a new tab 2. but tab 1 does not show up in tab 2. what should i do now to show tab options in the title bar? (I did not ask about vertical or horizontal splitting)