I reiterate the point, “Call around.”
For example, Progressive has two divisions; one for vehicles, one for RVs. They don’t talk to each other. SMB is one of the manufacturers that Progressive will insure as an RV. My longtime insurance company, Liberty Mutual, wouldn’t touch it even through they previously insured our teardrop trailer. A LM broker found a company ... turned out to be Progressive. Same with Good Sam, Progressive, also. There are other options out there, too.
Follow some of the older threads on the Forum where there is a lot of useful information. Good luck.
2019 Transit 350 HR Eco Quigley 4X4