diff --git a/application/Preorder/Preorder.php b/application/Preorder/Preorder.php
index 2439cd9c9..fd19c7f50 100644
--- a/application/Preorder/Preorder.php
+++ b/application/Preorder/Preorder.php
@@ -60,7 +60,9 @@ class Preorder extends mfBaseModel {
 
         $this->setOrCreateOaid();
         if($this->oaid != $old_oaid) {
+            $this->resetSaveNesting();
             $this->save();
+            return true;
         }
 
         //TODO: history start
@@ -334,11 +336,16 @@ class Preorder extends mfBaseModel {
         }
 
         if(!$this->adb_wohneinheit_id) {
+            $this->oaid = null;
             return false;
         }
 
         $wohneinheit = new ADBWohneinheit($this->adb_wohneinheit_id);
 
+        if(!$wohneinheit) {
+            return true;
+        }
+
         if($this->oaid) {
             // If current OAID is from correct Origin then do nothing
             if($campaign->oaid_origin == "thetool") {
@@ -358,6 +365,10 @@ class Preorder extends mfBaseModel {
                         if(!$wohneinheit->oaid) {
                             $wohneinheit->oaid = $current_oaid->oaid;
                             $wohneinheit->save();
+                        } elseif($wohneinheit->oaid != $this->oaid) {
+                            // also check if wohneinheit has a different OAID and set it in the Preorder
+                            // No need to update OAID object, it should be correct already, because Wohneinheit is the source of oaid data,
+                            $this->oaid = $wohneinheit->oaid;
                         }
                         return true;
                     }