Thanks for the warning. Sorry that happened to you. I hope the replies here will give you some insight.
I seldom pay in advance, but sometimes leave money in plain sight. A new provider will see that and be reassured. My regulars know they can take the money without asking when they leave.
A few years ago I met a new escort in a hotel in the winter. He picked up the cash from the dresser when arriving, and I decided not to say anything. Then a minute later he said he needed to make a phone call, stepped into the hallway, and kept walking. He took my money and never came back.
I texted him to say he was a thief. He told me the money would buy his son a Christmas present and I should feel good about that.
Lesson learned, I was more cautious about first meetings after that experience.