How do you know that a domme isn’t a scammer and verified correctly?

I have this issue sometimes that a domme will verify herself through sending a video of her saying something specific I told her to say or she will send a picture with a piece of paper with a specific word, but they still do stuff that makes them feel sus to me and like a potential scammer. Like, I would be pretty certain that they are real, but some of the subtle stuff they do feels sketchy like sending me weird gc links or telling me small lies. Am I just being paranoid or are some of them actually fishy? What could I do to make sure they are legit?