you have to halt the plug pipeline explicitly

lib/philomena_web/controllers/api/json/image/featured_controller.ex

@@ -23,6 +23,7 @@ defmodule PhilomenaWeb.Api.Json.Image.FeaturedController do
         conn
         |> put_status(:not_found)
         |> text("")
+        |> halt()
 
       _ ->
         interactions = Interactions.user_interactions([featured_image], user)

lib/philomena_web/controllers/filter/hide_controller.ex

@@ -47,6 +47,7 @@ defmodule PhilomenaWeb.Filter.HideController do
         conn
         |> put_status(:forbidden)
         |> text("")
+        |> halt()
     end
   end
 end

lib/philomena_web/controllers/filter/spoiler_controller.ex

@@ -47,6 +47,7 @@ defmodule PhilomenaWeb.Filter.SpoilerController do
         conn
         |> put_status(:forbidden)
         |> text("")
+        |> halt()
     end
   end
 end

lib/philomena_web/controllers/image/delete_controller.ex

@@ -59,6 +59,7 @@ defmodule PhilomenaWeb.Image.DeleteController do
         conn
         |> put_flash(:error, "Cannot change hide reason on a non-hidden image!")
         |> redirect(to: Routes.image_path(conn, :show, conn.assigns.image))
+        |> halt()
     end
   end
 

lib/philomena_web/controllers/image/feature_controller.ex

@@ -24,6 +24,7 @@ defmodule PhilomenaWeb.Image.FeatureController do
         conn
         |> put_flash(:error, "Cannot feature a hidden image.")
         |> redirect(to: Routes.image_path(conn, :show, conn.assigns.image))
+        |> halt()
 
       _false ->
         conn

lib/philomena_web/controllers/image/file_controller.ex

@@ -35,6 +35,7 @@ defmodule PhilomenaWeb.Image.FileController do
         conn
         |> put_flash(:error, "Cannot replace a hidden image.")
         |> redirect(to: Routes.image_path(conn, :show, conn.assigns.image))
+        |> halt()
 
       _false ->
         conn

lib/philomena_web/controllers/image_controller.ex

@@ -188,7 +188,7 @@ defmodule PhilomenaWeb.ImageController do
           "The image you were looking for has been marked a duplicate of the image below"
         )
         |> redirect(to: Routes.image_path(conn, :show, image.duplicate_id))
-        |> Plug.Conn.halt()
+        |> halt()
 
       true ->
         conn

lib/philomena_web/controllers/profile/commission_controller.ex

@@ -149,6 +149,7 @@ defmodule PhilomenaWeb.Profile.CommissionController do
         conn
         |> put_flash(:error, "You must have a verified user link to create a commission listing.")
         |> redirect(to: Routes.commission_path(conn, :index))
+        |> halt()
     end
   end
 end

lib/philomena_web/controllers/tag_controller.ex

@@ -153,6 +153,7 @@ defmodule PhilomenaWeb.TagController do
           "This tag (\"#{conn.assigns.tag.name}\") has been aliased into the tag \"#{tag.name}\"."
         )
         |> redirect(to: Routes.tag_path(conn, :show, tag))
+        |> halt()
     end
   end
 end

lib/philomena_web/plugs/ensure_user_enabled_plug.ex

@@ -31,6 +31,7 @@ defmodule PhilomenaWeb.EnsureUserEnabledPlug do
     conn
     |> Plug.delete()
     |> Controller.redirect(to: Routes.pow_session_path(conn, :new))
+    |> Conn.halt()
   end
 
   defp maybe_halt(_any, conn), do: conn