How do I make TextEdit open documents in a new window in Sonoma?

I've just got a new iMac, running Sonoma. My old iMac was running Catalina. When I open an .rtf document while another document is also open in TextEdit, it opens the second document in a new tab in the existing window, rather than in a new window like it did in Catalina. I'd prefer to open documents in a new window by default. I can't see anything in the TextEdit menus or settings dialogue to control this. Is it possible to change this behaviour, or is this yet another feature Apple have taken away?