What context did you set up? Did you set the expectation that it was a reference monitor for security/safety decisions? Did you imply a specific cast of characters, only revealing the existence of a female-coded doctor deep into the context? You can get this kind of result from bias, but you can also get it from implicit search constraint-solving.
Yes, it was explicitly set up as "_only_ provide X context if the user is a doctor." A bit more complex, yes, but basically that's what the setup was.