Insurance for a fixed location trailer

I purchased a Cedar Creek Cottage TT a year ago and insured it with Progressive. The Cottage has holding tanks water tanks and everything saying it's an RV TT. However after a month I got a cancellation notice saying the won't insure that type of trailer.

I switched to Good SAMs, they consider my unit a destination trailer and had no problem providing insurance staying on our lot. As with rjf7g it must be registered, not tied down (except temporary tie downs as required during hurricane season in Key West) and wheels on ground.