Off-site redirect URL host portion ignored

Problem/Motivation

Redirect to an offsite page goes to own site with path string from configured redirect.

Steps to reproduce

- Create a redirect with a local path (say /some-uri), an offsite "To" (say https://off.site.gov/their/path), redirect status 302 or 307.
- Visit https://my.site.edu/some-uri, and up at https://my.site.edu/their/path

This behavior is the same in 8.x-1.08 and 8.x-1.11. I don't see an alias that might interfere. I've scanned our custom code, and nothing jumps out. Of course it would be odd for misbehavior of this sort to continue to exist for that long, so it's entirely possible there's some internal interaction.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes