Rewrite/200 + splat turns 301

Hi,

I’m trying to do a rewrite to a 3rd party service using a TOML file. If I do a rewrite (redirect + 200) to a specific URL it works. However if I add a splat to the URL it turns into a redirect (301).

Works, proxies to service, returns 200:

[[redirects]]
  from = "/test"
  to = "http://otherserice.com/test"
  status = 200

Doesn’t work, returns 301:

[[redirects]]
  from = "/test/*"
  to = "http://otherserice.com/test/:splat"
  status = 200

In each example above, they are the entire contents of the TOML file.

I do not see anything in the docs that say rewrite will not work with a splat. Any ideas?

Thanks