diff -u b/core/modules/taxonomy/src/TermForm.php b/core/modules/taxonomy/src/TermForm.php
--- b/core/modules/taxonomy/src/TermForm.php
+++ b/core/modules/taxonomy/src/TermForm.php
@@ -47,6 +47,9 @@
 
       $tree = $taxonomy_storage->loadTree($vocabulary->id());
       $options = array('<' . $this->t('root') . '>');
+      if (empty($parent)) {
+        $parent = array(0);
+      }
 
       foreach ($tree as $item) {
         if (!in_array($item->tid, $exclude)) {
@@ -106,8 +109,10 @@
     // Prevent leading and trailing spaces in term names.
     $term->setName(trim($term->getName()));
 
-    // Assign parents with proper delta values starting from 0.
-    $term->parent = array_keys($form_state->getValue('parent'));
+    // Assign parents with proper delta values starting from 0 and filter out
+    // the pre-selected root as it will not be saved (target_id = 0) and will
+    // only cause hasTranslationChanges to return a false result.
+    $term->parent = array_filter(array_keys($form_state->getValue('parent')));
 
     return $term;
   }