fastlane-plugin-firebase_app_distribution: iOS build succeeds but ipa file does not seem to be accessible from Firebase

I have an iOS build that I am running with CircleCI with the intention for it to be distributed to testers via Firebase.

The build succeeds and I get confirmation the ipa has been uploaded to FIrebase, the specified tester(s) get an email notification, but when they try to access the app they simply get a message saying there is no app.

The Firebase console on my end updates with a distribution and the tester information, but from what I can tell there there does not seem to be any ipa attached to the distribution.

I have ssh’d into the passing Circle build to ensure the ipa is created, and have downloaded it manually.

Please see below my Fastfile, config.yml and build log, is there something I am missing?

Fastfile:

platform :ios do
  before_all do
    setup_circle_ci
  end

  lane :beta do
    match(
      type: "appstore",
      team_id: TEAM,
      app_identifier: APP_ID,
      output_path: "./builds",
      keychain_name: "fastlane_tmp_keychain",
      readonly: is_ci
    )
    settings_to_override = {
      :BUNDLE_IDENTIFIER => APP_ID,
      :PROVISIONING_PROFILE_SPECIFIER => PROFILE,
      :DEVELOPMENT_TEAM => TEAM
    }
    update_project_team( 
      teamid: CredentialsManager::AppfileConfig.try_fetch_value(:team_id)
    )
    increment_build_number(xcodeproj: "MyApp.xcodeproj")
    build_app(
      clean: true,
      export_method: "app-store",
      build_path: "./builds",
      output_directory: "./builds",
      xcargs: settings_to_override,
      scheme: "My app",
      export_options: {
        signingCertificate: SIGNING_CERTIFICATE,
        provisioningProfiles: {
          APP_ID => PROFILE
        }
      }
    )
    firebase_app_distribution(
      app: FIREBASE_APP_ID,
      testers: TESTER,
      release_notes: "New updates to test",
      ipa_path: "/Users/distiller/repo/ios/builds/myIpa.ipa",
      firebase_cli_path: "/Users/distiller/repo/node_modules/.bin/firebase"
    )
  end
end

Circle config:

version: 2
jobs:
    build:
        macos:
            xcode: '10.3.0'

        working_directory: ~/repo
        environment:
            FASTLANE_LANE: beta

        steps:
            - checkout
            - run:
                  # We can't set this using an image because that makes the build run in a Linux box
                  name: 'Manually set ruby version to 2.6.3'
                  command: echo "ruby-2.6.3" > ~/.ruby-version
            - run:
                  name: install bundler
                  command: gem install bundler --version 2.0.1
            - run: cd ./ios && bundle install
            - run:
                  # This is necessary to ensure that native modules will compile properly
                  name: 'Install specific Node and NPM versions'
                  command: |
                      curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.1/install.sh | bash
                        echo 'export NVM_DIR="$HOME/.nvm"' >> $BASH_ENV
                        echo '[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"' >> $BASH_ENV
                        echo 'nvm install v10.17.0' >> $BASH_ENV
                        echo 'nvm alias default v10.17.0' >> $BASH_ENV
            - run:
                  name: 'Install JS dependencies and run post-install steps'
                  command: npm install
            - run:
                  name: Fastlane
                  command: cd ./ios && bundle exec fastlane $FASTLANE_LANE

Circle build passing:

[09:41:51]: Successfully exported and compressed dSYM file
[09:41:51]: Successfully exported and signed the ipa file:
[09:41:51]: /Users/distiller/repo/ios/builds/Converge.ipa
[09:41:51]: ---------------------------------------
[09:41:51]: --- Step: firebase_app_distribution ---
[09:41:51]: ---------------------------------------
[09:41:56]: ▸ i  getting app details...
[09:41:57]: ▸ i  uploading distribution...
[09:42:10]: ▸ ✔  uploaded distribution successfully
[09:42:10]: ▸ i  adding release notes...
[09:42:11]: ▸ ✔  added release notes successfully
[09:42:11]: ▸ i  adding testers/groups...
[09:42:11]: ▸ ✔  added testers/groups successfully

+------+---------------------------+-------------+
|                fastlane summary                |
+------+---------------------------+-------------+
| Step | Action                    | Time (in s) |
+------+---------------------------+-------------+
| 1    | default_platform          | 0           |
| 2    | setup_circle_ci           | 0           |
| 3    | is_ci                     | 0           |
| 4    | match                     | 2           |
| 5    | update_project_team       | 0           |
| 6    | increment_build_number    | 2           |
| 7    | build_app                 | 654         |
| 8    | firebase_app_distribution | 20          |
+------+---------------------------+-------------+