Confirm connection monitor subscription on open

actioncable/lib/action_cable/connection/base.rb

@@ -154,7 +154,7 @@ module ActionCable
         def handle_open
           connect if respond_to?(:connect)
           subscribe_to_internal_channel
-          beat
+          confirm_connection_monitor_subscription
 
           message_buffer.process!
           server.add_connection(self)
@@ -173,6 +173,13 @@ module ActionCable
           disconnect if respond_to?(:disconnect)
         end
 
+        def confirm_connection_monitor_subscription
+          # Send confirmation message to the internal connection monitor channel.
+          # This ensures the connection monitor state is reset after a successful
+          # websocket connection.
+          transmit ActiveSupport::JSON.encode(identifier: ActionCable::INTERNAL[:identifiers][:ping], type: ActionCable::INTERNAL[:message_types][:confirmation])
+        end
+
         def allow_request_origin?
           return true if server.config.disable_request_forgery_protection
 

actioncable/test/connection/base_test.rb

@@ -56,7 +56,7 @@ class ActionCable::Connection::BaseTest < ActionCable::TestCase
     run_in_eventmachine do
       connection = open_connection
 
-      connection.websocket.expects(:transmit).with(regexp_matches(/\_ping/))
+      connection.websocket.expects(:transmit).with({ identifier: "_ping", type: "confirm_subscription" }.to_json)
       connection.message_buffer.expects(:process!)
 
       connection.process