diff -u b/core/modules/file/src/Plugin/Field/FieldFormatter/FileAudioFormatter.php b/core/modules/file/src/Plugin/Field/FieldFormatter/FileAudioFormatter.php
--- b/core/modules/file/src/Plugin/Field/FieldFormatter/FileAudioFormatter.php
+++ b/core/modules/file/src/Plugin/Field/FieldFormatter/FileAudioFormatter.php
@@ -8,7 +8,7 @@
  * @FieldFormatter(
  *   id = "file_audio",
  *   label = @Translation("Audio"),
- *   description = @Translation("Render the file using an HTML5 audio tag."),
+ *   description = @Translation("Display the file using an HTML5 audio tag."),
  *   field_types = {
  *     "file"
  *   }
diff -u b/core/modules/file/src/Plugin/Field/FieldFormatter/FileMediaFormatterBase.php b/core/modules/file/src/Plugin/Field/FieldFormatter/FileMediaFormatterBase.php
--- b/core/modules/file/src/Plugin/Field/FieldFormatter/FileMediaFormatterBase.php
+++ b/core/modules/file/src/Plugin/Field/FieldFormatter/FileMediaFormatterBase.php
@@ -160,7 +160,7 @@
    */
   protected static function mimeTypeApplies($mime_type) {
     list($type) = explode('/', $mime_type, 2);
-    return ($type === static::getMediaType());
+    return $type === static::getMediaType();
   }
 
   /**
@@ -186,7 +186,7 @@
       if (static::mimeTypeApplies($file->getMimeType())) {
         $source_attributes = new Attribute();
         $source_attributes
-          ->setAttribute('src', file_create_url($file->getFileUri()))
+          ->setAttribute('src', file_url_transform_relative(file_create_url($file->getFileUri())))
           ->setAttribute('type', $file->getMimeType());
         if ($this->getSetting('multiple_file_display_type') === 'tags') {
           $source_files[] = [
diff -u b/core/modules/file/src/Plugin/Field/FieldFormatter/FileVideoFormatter.php b/core/modules/file/src/Plugin/Field/FieldFormatter/FileVideoFormatter.php
--- b/core/modules/file/src/Plugin/Field/FieldFormatter/FileVideoFormatter.php
+++ b/core/modules/file/src/Plugin/Field/FieldFormatter/FileVideoFormatter.php
@@ -10,7 +10,7 @@
  * @FieldFormatter(
  *   id = "file_video",
  *   label = @Translation("Video"),
- *   description = @Translation("Render the file using an HTML5 video tag."),
+ *   description = @Translation("Display the file using an HTML5 video tag."),
  *   field_types = {
  *     "file"
  *   }
diff -u b/core/modules/file/tests/src/Functional/Formatter/FileAudioFormatterTest.php b/core/modules/file/tests/src/Functional/Formatter/FileAudioFormatterTest.php
--- b/core/modules/file/tests/src/Functional/Formatter/FileAudioFormatterTest.php
+++ b/core/modules/file/tests/src/Functional/Formatter/FileAudioFormatterTest.php
@@ -37,7 +37,7 @@
 
     $file_url = file_url_transform_relative(file_create_url($file->getFileUri()));
     $this->assertSession()->elementExists('css', 'audio[controls="controls"]');
-    $this->assertSession()->elementExists('css', "audio > source[src*='$file_url'][type='audio/mpeg']");
+    $this->assertSession()->elementExists('css', "audio > source[src='$file_url'][type='audio/mpeg']");
   }
 
 }
diff -u b/core/modules/file/tests/src/Functional/Formatter/FileVideoFormatterTest.php b/core/modules/file/tests/src/Functional/Formatter/FileVideoFormatterTest.php
--- b/core/modules/file/tests/src/Functional/Formatter/FileVideoFormatterTest.php
+++ b/core/modules/file/tests/src/Functional/Formatter/FileVideoFormatterTest.php
@@ -37,7 +37,7 @@
 
     $file_url = file_url_transform_relative(file_create_url($file->getFileUri()));
     $this->assertSession()->elementExists('css', 'video[controls="controls"]');
-    $this->assertSession()->elementExists('css', "video > source[src*='$file_url'][type='video/mp4']");
+    $this->assertSession()->elementExists('css', "video > source[src='$file_url'][type='video/mp4']");
   }
 
 }