Sorry no one has chimed in here, perhaps you can add some detail to your post to encourage some thoughtful responses. Does the problem occur on park water settings and on internal water from your fresh tank pushed by your pump, or just on one. Do you have normal water flow out of faucets and showers? Doesn't sound like it to me, but macerating toilets have a variety of settings for low water usage that may be playing a part as well. Do you have the user manual for your toilet available?