The root cause was LiveView routes not being wrapped in a live_session block, and using <a href="..."> instead of <.link navigate={...}> for internal navigation links. Without live_session, every navigation between LiveView pages causes a full page reload, which creates a new WebSocket connection.

Fix:

1. Wrap LiveView routes in live_session:

live_session :public do
  live "/", HomeLive
  live "/about", AboutLive
end

2. Use <.link navigate={...}> instead of <a href="..."> for internal links:

<.link navigate={~p"/about"}>About</.link>

This ensures navigation happens over the existing WebSocket connection (client-side) instead of triggering full page reloads that create new WebSocket connections.