I thought this same thing might happen on my 2018 Anthem. Seems like a bad design. This solution may not be original, but I attached a little bungee cord from the plastic door frame to the macerator hose door with a length that keeps it from opening far enough to be caught by the water bay door. Works great, does not get in the way and is not visible when the macerator door is closed.
Dennis & Nancy & Gizmo (Havanese)
2018 Victory Blue Anthem 44W