Put the tip of your mouse exactly at the edge of a button. Imagine a line: if you click on the one side of it ("A" side), you press a button of the menu; if you click on the other side of it ("B" side), nothing happens. Now put the tip of your mouse on the "B" side, press the (for me) left mouse button, keep it down and drag. Position the menu to your liking and release the button.
Edit: (Yes, I'm crazy but I have just tested it IG and it works

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