My guess is that people are moving over to VRBO because of AirBnB pulling out of San Francisco and New York. I own in both NYC and San Francisco, with HOTEL timeshares that should not be restricted to 30 day rentals, but AirBnB decided to just leave these markets entirely and ban all properties even if an established short-term rental.
So now it's back to VRBO, eBay & Redweek.
This may explain the reduction in people looking at your rental.