So, if the planet-that-shall-not-be-named does indeed “roll” in its orbit so that its “polar axis” is near-parallel to the ecliptic normal plane of the rest of the planets, why do these band tilt at a significant angle to the horizontal plane?
Because of the camera angle. Sorry, couldn’t find a diagram for Uranus, but this shows Venus and Mercury, you’ll get the idea:
https://astrobob.areavoices.com/2011/11/12/meet-the-ecliptic-one-of-astronomys-scariest-concepts/