It's kinda normal to YOUR particular Winnebago due to fact that the wheelbase is too short for THAT long of a body. I can tell just by looking at a normal direct view of the side of it. From the standpoint of better directional stability, your motorhome should either have a longer wheelbase, OR a shorter rear OVERHANG.
Winnebago, and other RV manufacturers, have to compromise the design, in order to be able to sell THAT much motorhome for THAT price.
BUT, there's several things you can do in order to make sure OTHER less important things are as they should be. I would start with adding dead weight/ballast to the front end in order to make sure there's maximum allowed weight on the FRONT tires. This you do in order to have maximum caster authority.