When Rhazes declines a request
Rhazes declines requests outside what it is built to do rather than improvising, and why an honest refusal is the safer behaviour.
Updated
Not every request gets an answer. Where something falls outside what Rhazes is built to do, it declines rather than producing something unreliable and presenting it confidently.
This is deliberate. For a clinical tool, an honest refusal is safer than a plausible answer to a question it should not be answering.
If you think a refusal is wrong, report it. A declined request that should have worked is exactly the sort of thing worth flagging. See Sending feedback or reporting a problem.