Why do owners decline bookings and how to prevent this?

I'm new to Rover and I excitingly received a request from an owner to drop in on her 5 dogs for a couple days next week. I messaged them saying I could do it, asked them for specifics for the drop in, and offered a meet and greet. A couple hours later they declined me and I'm not sure what I did wrong! How can I prevent this in the future?