I believe it. In the customer service industry, the tendency to not be "on" (make up, hair, seductive attitude" is a mark of not only job stress but also indicates that your SP sees you as a series of $ bills rather than a fun, exciting experience.
(That they are selling)
It's a tricky balancing act for the ladies in the industry and frankly, seeing only one side of men, day in day out will skew someone's perspective of what healthy sexual encounters are in the real world. It's a trade off for $ and once the best clients leave because they feel under served, then it's even harder to bring them back. It's economics 101.
If you feel that she's having a bad day/week/ burned out, as a client you are under no obligation to pay her anything. You can be polite but firm by saying "I've loved our time together in the past but I'm concerned about yiu right now. I think we should rain cheque" is what clients are entitled to.