diff -u b/core/modules/file/file.es6.js b/core/modules/file/file.es6.js
--- b/core/modules/file/file.es6.js
+++ b/core/modules/file/file.es6.js
@@ -7,7 +7,7 @@
  * prevents separate file fields from accidentally uploading files).
  */
 
-(function ($, Drupal, debounce) {
+(function ($, Drupal) {
   /**
    * Attach behaviors to the file fields passed in the settings.
    *
@@ -85,13 +85,13 @@
   Drupal.behaviors.fileButtons = {
     attach(context) {
       const $context = $(context);
-      $context.find('.js-form-submit').on('mousedown.fileButtons', Drupal.file.disableFields);
-      $context.find('.js-form-managed-file .js-form-submit').on('mousedown.fileButtons', Drupal.file.progressBar);
+      $context.find('.js-form-submit').on('replaceProgressBar.fileButtons', Drupal.file.disableFields);
+      $context.find('.js-form-managed-file .js-form-submit').on('replaceProgressBar.fileButtons', Drupal.file.progressBar);
     },
     detach(context) {
       const $context = $(context);
-      $context.find('.js-form-submit').off('mousedown.fileButtons');
-      $context.find('.js-form-managed-file .js-form-submit').off('mousedown.fileButtons');
+      $context.find('.js-form-submit').off('replaceProgressBar.fileButtons');
+      $context.find('.js-form-managed-file .js-form-submit').off('replaceProgressBar.fileButtons');
     },
   };
 
@@ -167,10 +167,10 @@
      *   The event triggered. For example `change.autoFileUpload`.
      */
     triggerUploadButton(event) {
-      // Calling event handlers before the form is submitted. Triggering
-      // mousedown on submit button may start an asynchronous upload thread.
       $(event.target).closest('.js-form-managed-file').find('.js-form-submit')
-        .trigger('mousedown.fileButtons')
+        // Setup required elements for progress bar.
+        .trigger('replaceProgressBar')
+        // Trigger ajax submission.
         .trigger('mousedown');
     },
 
@@ -182,7 +182,7 @@
      * @param {jQuery.Event} event
      *   The event triggered, most likely a `mousedown` event.
      */
-    disableFields: debounce(function (event) {
+    disableFields(event) {
       const $clickedButton = $(this).findOnce('ajax');
 
       // Only disable upload fields for Ajax buttons.
@@ -210,7 +210,7 @@
       setTimeout(() => {
         $fieldsToTemporarilyDisable.prop('disabled', false);
       }, 1000);
-    }, 100, true),
+    },
 
     /**
      * Add progress bar support if possible.
@@ -220,7 +220,7 @@
      * @param {jQuery.Event} event
      *   The event triggered, most likely a `mousedown` event.
      */
-    progressBar: debounce(function (event) {
+    progressBar(event) {
       const $clickedButton = $(this);
       const $progressId = $clickedButton.closest('div.js-form-managed-file').find('input.file-progress');
       if ($progressId.length) {
@@ -238,7 +238,7 @@
       setTimeout(() => {
         $clickedButton.closest('div.js-form-managed-file').find('div.ajax-progress-bar').slideDown();
       }, 500);
-    }, 100, true),
+    },
 
     /**
      * Open links to files within forms in a new window.
@@ -257 +257 @@
-})(jQuery, Drupal, Drupal.debounce);
+}(jQuery, Drupal));
diff -u b/core/modules/file/file.js b/core/modules/file/file.js
--- b/core/modules/file/file.js
+++ b/core/modules/file/file.js
@@ -5,7 +5,7 @@
 * @preserve
 **/
 
-(function ($, Drupal, debounce) {
+(function ($, Drupal) {
   Drupal.behaviors.fileValidateAutoAttach = {
     attach: function attach(context, settings) {
       var $context = $(context);
@@ -49,13 +49,13 @@
   Drupal.behaviors.fileButtons = {
     attach: function attach(context) {
       var $context = $(context);
-      $context.find('.js-form-submit').on('mousedown.fileButtons', Drupal.file.disableFields);
-      $context.find('.js-form-managed-file .js-form-submit').on('mousedown.fileButtons', Drupal.file.progressBar);
+      $context.find('.js-form-submit').on('replaceProgressBar.fileButtons', Drupal.file.disableFields);
+      $context.find('.js-form-managed-file .js-form-submit').on('replaceProgressBar.fileButtons', Drupal.file.progressBar);
     },
     detach: function detach(context) {
       var $context = $(context);
-      $context.find('.js-form-submit').off('mousedown.fileButtons');
-      $context.find('.js-form-managed-file .js-form-submit').off('mousedown.fileButtons');
+      $context.find('.js-form-submit').off('replaceProgressBar.fileButtons');
+      $context.find('.js-form-managed-file .js-form-submit').off('replaceProgressBar.fileButtons');
     }
   };
 
@@ -90,10 +90,9 @@
       }
     },
     triggerUploadButton: function triggerUploadButton(event) {
-      $(event.target).closest('.js-form-managed-file').find('.js-form-submit').trigger('mousedown.fileButtons').trigger('mousedown');
+      $(event.target).closest('.js-form-managed-file').find('.js-form-submit').trigger('replaceProgressBar').trigger('mousedown');
     },
-
-    disableFields: debounce(function (event) {
+    disableFields: function disableFields(event) {
       var $clickedButton = $(this).findOnce('ajax');
 
       if (!$clickedButton.length) {
@@ -110,9 +109,8 @@
       setTimeout(function () {
         $fieldsToTemporarilyDisable.prop('disabled', false);
       }, 1000);
-    }, 100, true),
-
-    progressBar: debounce(function (event) {
+    },
+    progressBar: function progressBar(event) {
       var $clickedButton = $(this);
       var $progressId = $clickedButton.closest('div.js-form-managed-file').find('input.file-progress');
       if ($progressId.length) {
@@ -131,9 +129,8 @@
-    }, 100, true),
-
+    },
     openInNewWindow: function openInNewWindow(event) {
       event.preventDefault();
       $(this).attr('target', '_blank');
       window.open(this.href, 'filePreview', 'toolbar=0,scrollbars=1,location=1,statusbar=1,menubar=0,resizable=1,width=500,height=550');
     }
   };
-})(jQuery, Drupal, Drupal.debounce);
\ No newline at end of file
+})(jQuery, Drupal);
\ No newline at end of file
reverted:
--- b/core/modules/file/file.libraries.yml
+++ a/core/modules/file/file.libraries.yml
@@ -7,4 +7,3 @@
     - core/jquery.once
     - core/drupal
     - core/drupalSettings
-    - core/drupal.debounce