Fix submission is newly created on save (#440)

* Fix submission is newly created on save

* Do it on save

---------

Co-authored-by: Ryan Mitchell <[email protected]>

Author: Lampone

src/Forms/Submission.php

@@ -84,7 +84,10 @@ public function save()
 
         $model = $this->toModel();
         $model->save();
-        $isNew = $model->wasRecentlyCreated;
+
+        if ($isNew = $model->wasRecentlyCreated) {
+            $this->id = $model->getKey();
+        }
 
         $this->model($model->fresh());