In my experience changes to the controllers usually recompile when the page is reloaded, but the controllers don’t recompile directly after code changes because they aren’t being watched for changes by live_reload, but if needed, you should be able to add them in config/dev.exs.

# config/dev.exs

...
# Watch static and templates for browser reloading.
config :my_app, MyApp.Endpoint,
  live_reload: [
    patterns: [
      ~r{priv/static/.*(js|css|png|jpeg|jpg|gif|svg)$},
      ~r{priv/gettext/.*(po)$},
+     ~r{lib/my_app_web/controllers/.*(ex)$},
      ~r{lib/my_app_web/views/.*(ex)$},
      ~r{lib/my_app_web/templates/.*(eex)$}
    ]
  ]

...

I’m guessing they were excluded from the live_reload patterns for a reason. Too many errors that way maybe?

If other projects on the same computer work, then you probably have the system level dependencies.

Then I’d try the usual, simply remove deps and _build folder and try again.

Huh? I run through tmux excessively, nor do I see any way that tmux would cause such an issue, can you elaborate more? o.O?