ruby2.7へのupdateの際、LoadErrorが起きる

Question

本番環境のrubyを2.6から2.7にバージョンアップしようとしています。
一気にgemをupdateせず、circleciを使用してlintとrspecがこける都度、該当のgemをupdateすることをエラーが起きなくなるまで繰り返すというような変更作業を行なっています。

その中で以下のエラーを解決できずにいます。

LoadError: Unable to autoload constant CaseReports::FavoritesAPI, expected /home/circleci/***/app/api/web/case_reports/favorites_api.rb to define it
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:511:in `load_missing_constant'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/active_support.rb:60:in `block in load_missing_constant'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/active_support.rb:16:in `allow_bootsnap_retry'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/active_support.rb:59:in `load_missing_constant'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:195:in `const_missing'
/home/circleci/***/app/api/app/v2.rb:13:in `<class:V2>'
/home/circleci/***/app/api/app/v2.rb:1:in `<main>'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:291:in `block in require'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:257:in `load_dependency'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:291:in `require'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:378:in `block in require_or_load'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:37:in `block in load_interlock'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies/interlock.rb:14:in `block in loading'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/concurrency/share_lock.rb:151:in `exclusive'
/home/circleci/***/vendor/bundle/ruby/2.7.0/gems/activesupport-5.2.2/lib/active_support/dependencies/interlock.rb:13:in `loading'

エラー箇所はapp/api/app/v2.rb内ですが、これまで本番アプリケーションでもApp::V2::CaseReports::FavoritesAPIとして動作しておりましたが、update作業の中で定数がうまく読まれないようになったようです。

# v2.rb
.
.
.
  mount App::V2::BannersAPI
  mount App::V2::BlockingsAPI
  mount App::V2::CaseReports::FavoritesAPI
  mount App::V2::CaseReports::ClipAPI
  mount App::V2::CaseReportsAPI
  mount App::V2::ClinicGroupsAPI
.
.
.

どなたか知恵を貸しいただけませんでしょうか。
update作業の概要を以下にまとめておきます。

---

• circleciで用いるimageをruby:2.6.0-node-browsersからruby:2.7.0-node-browsersに変更

lint:
    working_directory: ~/***
    resource_class: large
    docker:
      - image: circleci/ruby:2.7.0-node-browsers

• エラーの原因となっているgemをupdate
  • update bundler
  • update bootsnap
  • update shoulda-matchers
  • update config
  • update capybara
  • update grape ← ここから先に進めないです