Changes in federal lending regulations a couple years ago made it more difficult for banks (etc) to make loans to full timers. Some lenders simply don't want to bother with the new requirements. Small lenders may not even be aware that the federal regs appear to classify an RV loan as a "mortgage" and require an escrow, even though the financial industry does not. If the lender calls it a vehicle loan, the rules are different/simpler, but they might run afoul of the feds.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL