OAuth not respecting path or prefix

[forgot]

I'm attempting to user OAuth with Feathers behind /api, but the internal routes created don't seem to respect anything added to path or prefix in the Grant configuration. Everything works in localhost, but I can't figure out how to get it to work with /api. I've been trying to debug this for the last three days and,

I've tried setting path, prefix, origin, callback, redirect_uri, in every combination that I can think of, but nothing seems to work.

Here are the relevant parts from the production.json config file.

 "oauth": {
      "redirect": "/home",
      "defaults": {
        "prefix": "/api"
      },
      "github": {
        "key": "GITHUB_KEY",
        "secret": "GITHUB_SECRET",
        "callback": "/api/oauth/github/callback",
        "redirect_uri": "/api/oauth/github/callback"
      }
}

I've also tried setting everything explicitly, but still nothing...

Calling /api/oauth/github redirects to /oauth/connect/github?, which throws a 404. If I add the /api to the beginning, I get redirected to Github for login.

I've read through the documentation for Feathers and for Grant several times, but can't come up with a solution. I've seen a few other issues here or questions on StackOverflow with similar problems, but can't find an answer. Any insights as to how I should accomplish this?

[daffl]

Probably the same issue as #2031

[forgot]

Closing to consolidate discussion in the above linked issue