Bug? If I resize the window to force the mobile site, click the menu, then resize it back out again, the mobile menu reappears in the left-hand column. Which I actually quite like and to my mind would be good to be there permanently, but it covers up prospective ad space and doubt it’s intended behaviour.
Also, resizing in Edge (where I’ve no premier login or other add-ons) it properly goes to shit. Adverts cover half the screen, the menu shoves all the content offscreen, and resizing back out with the menu open causes all the content to fall off the bottom.