I recently purchased a new Hoover Conquest vacuum w/ the paper bag insert. (Hoover is making them again now) The top outer bag slides off the metal cross piece meant for holding it up. The remedy is a 1/4″ dowel rod 7″ long. Hold it in the (inside) upper part of the bag and slid the cross piece (holder) as before and problem solved. In the past I stomped on the cross piece (holder) until it wouldn’t slip off. FYI The dowel works better.
I ordered a new bag for my vac and it was shipped with the slide bar inside the bag. A little bell went off! Leave the slide bar on the inside and it works great.