[BUG] ApproveMan not selectable as reviewer

[EnergySRE]

Describe the bug
We've got a private repo (github.com/CamusEnergy/bando), for which we're trying to set up ApproveMan. I'm doing testing on my private fork with the same configuration (github.com/EnergySRE/bando), and seeing the same behavior in both places.

To Reproduce
Steps to reproduce the behavior:

1. Install ApproveMan with org-level permissions from GitHub Marketplace
2. Set "Repository access" to "All repositories"
3. Create a branch with the config below*
4. ApproveMan appears in the automated checks on the PR (screen shot below)
5. ApproveMan does not appear as an option on the reviewer list

I also tried adding ApproveMan as an authorized user to our organization, and receive a "no such user" error.

Expected behavior
I expect to be able to select ApproveMan as a reviewer and have it approve my PR based on the content of my config.

Screenshots

Automated checks pass:

ApproveMan not selectable as reviewer:

Additional context

Here's the config we're using:

ownership_rules:
  directory_matching_rules:
    - name: Markdown-only changes
      path: **/*.md
    - name: Doc folder
      path: doc/*