Unusual redirect status code
A hop in the chain used a status this scan does not treat as a normal redirect (301, 302, 303, 307, or 308).
Why it matters
Clients may not follow that hop the way you expect.
What to do
Use one of 301, 302, 303, 307, or 308, and prefer 301 or 308 for a permanent HTTPS move.
Reference
Redirect chains should preserve HTTPS and avoid open-redirect patterns.