For the hobby in-general, multiple numbers over time doesn't necessarily mean they're running a scam or setting you up, but it still raises enough concern that you might just want to look elsewhere.
Many providers have at least one number change, though. A lot of the time, they're still figuring things out early on and don't know the importance of holding onto a number, or maybe they rebrand themselves once they have a game plan. Still, that's usually a one-time thing.
All that said, t-gurls are generally flakier than cis girls, so I'd take multiple number changes as a big red flag.