Somehow the field collections migration query returns duplicate row from field_revision_ tables. Remove joining with field_revision_ and run query for each row to get parent entity type and id.

paragraphs-field-collection-migration-get-correct-number-of-revisions.patch

diff --git a/src/Plugin/migrate/source/d7/FieldCollectionItem.php b/src/Plugin/migrate/source/d7/FieldCollectionItem.php
index 50af07d..0dc9460 100644
--- a/src/Plugin/migrate/source/d7/FieldCollectionItem.php
+++ b/src/Plugin/migrate/source/d7/FieldCollectionItem.php
@@ -50,9 +50,6 @@ class FieldCollectionItem extends FieldableEntity {
     // bundles retrieved.
     if ($this->configuration['field_name']) {
       $query->condition('f.field_name', $this->configuration['field_name']);
-      $query->addField('fc', 'entity_type', 'parent_type');
-      $query->addField('fc', 'entity_id', 'parent_id');
-      $query->innerJoin('field_revision_' . $this->configuration['field_name'], 'fc', 'fc.' . $this->configuration['field_name'] . '_value = f.item_id and fc.' . $this->configuration['field_name'] . '_revision_id = f.revision_id');
     }
     return $query;
   }
@@ -66,6 +63,18 @@ class FieldCollectionItem extends FieldableEntity {
     $bundle = substr($bundle, FieldCollection::FIELD_COLLECTION_PREFIX_LENGTH);
     $row->setSourceProperty('bundle', $bundle);
 
+    if ($this->configuration['field_name']) {
+      $query = $this->select('field_revision_' . $this->configuration['field_name'], 'fc')
+        ->fields('fc', [
+          'entity_id',
+          'entity_type',
+        ])
+        ->range(0, 1);
+      $parent_row = $query->execute()->fetchObject();
+      $row->setSourceProperty('parent_id', $parent_row->entity_id);
+      $row->setSourceProperty('parent_type', $parent_row->entity_type);
+    }
+
     // Get Field API field values.
     $field_names = array_keys($this->getFields('field_collection_item', $row->getSourceProperty('field_name')));
     $item_id = $row->getSourceProperty('item_id');