As yes, the fascinating NO object! lol Soon as something is forbidden, it becomes the most fascinating place/thing on earth.
Mine got into doing all kinds of stuff and not listening. The only thing that worked for me in the end was telling them no and then putting them back in their pen for a bit. We went for maybe 3 days of them having very little free time because of Eddie’s stubbornness but I won and he finally learned that x behavior = time in the pen so he quit. However, mine had a big pen area so even though they hated being in it, they still had plenty of room.
But could you try this with him and his cage? Maybe leaving him there for 15 minutes at a time? That way he’s still getting a lot of free time (hopefully) but you have a way to “discipline” him. It may take a while, but he should eventually learn that being on the bed = cage time and will quit. Worth a shot at least.
It has also been suggested to use one of the loud noise mats they make for dogs and cats to keep them off the furniture. I know it’s been suggested on here to deter bunnies from other furniture. If you know he doesn’t like crinkling noises, maybe those crinkling mats would deter him too. Or aluminum foil. Even though a beds a big space. lol But maybe you could just put it in strategic spots.