Rails uninitialized constant because of bad namespace coming out of nowhere - ruby-on-rails

Question

I randomly run into errors where my framework complains about a missing class because of a bad namespace.
For some reasons Rails will try to look for class name namespaced from a different gem :
Suppose I have a ::ProfilesController in my root namespace, I sometimes get errors of
uninitialized constant Mongoid::Token::Collisions::ProfilesController
Where Mongoid::Token::Collisions (an example) is a module from a different gem used in models. I have several profiles controller declared the following way
class ::ProfilesController < Devise::RegistrationsController
class Registrations::ProfilesController < Devise::RegistrationsController
class Foo::ProfilesController < FooController
class Bar::ProfilesController < BarController
class Baz::Foo::ProfilesController < BazController
I don't understand how it's even possible to resolve ProfileController with the Mongoid::Token::Collisions namespace since I never write in my code ProfilesController as is without any namespace or the :: prefix
I actually had similar errors with different components. Usually the problem would go away when restarting the server. I'm wondering what may cause this behavior, which became more frequent. I'm not sure providing code would be of any help, the stack trace doesn't even start from my application code. Any idea where this may come from ?
ActionController::RoutingError (uninitialized constant Mongoid::Token::Collisions::ProfilesController):
activesupport (5.0.0.1) lib/active_support/inflector/methods.rb:283:in `const_get'
activesupport (5.0.0.1) lib/active_support/inflector/methods.rb:283:in `block in constantize'
activesupport (5.0.0.1) lib/active_support/inflector/methods.rb:266:in `each'
activesupport (5.0.0.1) lib/active_support/inflector/methods.rb:266:in `inject'
activesupport (5.0.0.1) lib/active_support/inflector/methods.rb:266:in `constantize'
actionpack (5.0.0.1) lib/action_dispatch/http/request.rb:93:in `controller_class'
actionpack (5.0.0.1) lib/action_dispatch/routing/route_set.rb:44:in `controller'
actionpack (5.0.0.1) lib/action_dispatch/routing/route_set.rb:30:in `serve'
actionpack (5.0.0.1) lib/action_dispatch/journey/router.rb:39:in `block in serve'
actionpack (5.0.0.1) lib/action_dispatch/journey/router.rb:26:in `each'
actionpack (5.0.0.1) lib/action_dispatch/journey/router.rb:26:in `serve'
actionpack (5.0.0.1) lib/action_dispatch/routing/route_set.rb:725:in `call'
rack-attack (5.0.1) lib/rack/attack.rb:147:in `call'
omniauth (1.3.2) lib/omniauth/strategy.rb:186:in `call!'
omniauth (1.3.2) lib/omniauth/strategy.rb:164:in `call'
omniauth (1.3.2) lib/omniauth/strategy.rb:186:in `call!'
omniauth (1.3.2) lib/omniauth/strategy.rb:164:in `call'
rack-tracker (1.1.0) lib/rack/tracker.rb:34:in `call'
rack-utm (0.0.2) lib/rack-utm.rb:59:in `call'
warden (1.2.6) lib/warden/manager.rb:35:in `block in call'
warden (1.2.6) lib/warden/manager.rb:34:in `catch'
warden (1.2.6) lib/warden/manager.rb:34:in `call'
rack (2.0.1) lib/rack/etag.rb:25:in `call'
rack (2.0.1) lib/rack/conditional_get.rb:25:in `call'
rack (2.0.1) lib/rack/head.rb:12:in `call'
rack (2.0.1) lib/rack/session/abstract/id.rb:222:in `context'
rack (2.0.1) lib/rack/session/abstract/id.rb:216:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/cookies.rb:613:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/callbacks.rb:38:in `block in call'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:97:in `__run_callbacks__'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:750:in `_run_call_callbacks'
activesupport (5.0.0.1) lib/active_support/callbacks.rb:90:in `run_callbacks'
actionpack (5.0.0.1) lib/action_dispatch/middleware/callbacks.rb:36:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:49:in `call'
web-console (3.3.1) lib/web_console/middleware.rb:131:in `call_app'
web-console (3.3.1) lib/web_console/middleware.rb:28:in `block in call'
web-console (3.3.1) lib/web_console/middleware.rb:18:in `catch'
web-console (3.3.1) lib/web_console/middleware.rb:18:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
railties (5.0.0.1) lib/rails/rack/logger.rb:36:in `call_app'
railties (5.0.0.1) lib/rails/rack/logger.rb:24:in `block in call'
activesupport (5.0.0.1) lib/active_support/tagged_logging.rb:70:in `block in tagged'
activesupport (5.0.0.1) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (5.0.0.1) lib/active_support/tagged_logging.rb:70:in `tagged'
railties (5.0.0.1) lib/rails/rack/logger.rb:24:in `call'
ahoy_matey (1.5.2) lib/ahoy/engine.rb:22:in `call_with_quiet_ahoy'
request_store (1.3.1) lib/request_store/middleware.rb:9:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/request_id.rb:24:in `call'
rack (2.0.1) lib/rack/method_override.rb:22:in `call'
rack (2.0.1) lib/rack/runtime.rb:22:in `call'
activesupport (5.0.0.1) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.0.0.1) lib/action_dispatch/middleware/static.rb:136:in `call'
rack (2.0.1) lib/rack/sendfile.rb:111:in `call'
rack-cors (0.4.0) lib/rack/cors.rb:80:in `call'
railties (5.0.0.1) lib/rails/engine.rb:522:in `call'
puma (3.6.0) lib/puma/configuration.rb:225:in `call'
puma (3.6.0) lib/puma/server.rb:578:in `handle_request'
puma (3.6.0) lib/puma/server.rb:415:in `process_client'
puma (3.6.0) lib/puma/server.rb:275:in `block in run'
puma (3.6.0) lib/puma/thread_pool.rb:116:in `block in spawn_thread'