title: Static files not rendering in Django 2.2 when debug disabled
body: <p>In Django 2.2, when I have <code>DEBUG=True</code>, all my static files render fine. But when I set <code>DEBUG=False</code> to test my production settings, all static file URLs suddenly return 404 errors.</p>
  
  <p>I have a project structure like:</p>
  
  <pre><code>myproject/
      myproject/
          settings.py
          urls.py
      manage.py
  static/
      thumbnails/
           image.png
  </code></pre>
  
  <p>My relevant static settings in <code>settings.py</code>:</p>
  
  <pre><code> STATIC_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', '..', 'static'))
  
   INSTALLED_APPS = [
  'django.contrib.admin',
  'django.contrib.auth',
  'django.contrib.contenttypes',
  'django.contrib.sessions',
  'django.contrib.messages',
  'django.contrib.staticfiles',
  ]
  
  STATICFILES_FINDERS = (
  'django.contrib.staticfiles.finders.FileSystemFinder',
  'django.contrib.staticfiles.finders.AppDirectoriesFinder',
  )
  ROOT_URLCONF = 'myproject.urls'
  STATIC_URL = '/static/'
  DEBUG = False
  </code></pre>
  
  <p>And my <code>urls.py</code> looks like:</p>
  
  <pre><code>import os
  
  from django.contrib import admin
  from django.conf.urls.static import static
  from django.conf import settings
  
  urlpatterns = [
      path('admin/', admin.site.urls),
  ]
  urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)
  </code></pre>
  
  <p>Why does a url like <code>http://localhost:8000/static/thumbnails/image.png</code> work fine when debug is on, but return a 404 when debug is off?</p>