--- apps/dav/lib/CalDAV/CalDavBackend.php.org	2024-09-28 19:03:58.997026797 +0200
+++ apps/dav/lib/CalDAV/CalDavBackend.php	2024-09-28 19:09:38.652912324 +0200
@@ -2331,16 +2331,18 @@
 	public function getCalendarObjectByUID($principalUri, $uid) {
 		$query = $this->db->getQueryBuilder();
 		$query->selectAlias('c.uri', 'calendaruri')->selectAlias('co.uri', 'objecturi')
+			->selectAlias('c.principaluri', 'principal')
 			->from('calendarobjects', 'co')
 			->leftJoin('co', 'calendars', 'c', $query->expr()->eq('co.calendarid', 'c.id'))
-			->where($query->expr()->eq('c.principaluri', $query->createNamedParameter($principalUri)))
-			->andWhere($query->expr()->eq('co.uid', $query->createNamedParameter($uid)))
+			->where($query->expr()->eq('co.uid', $query->createNamedParameter($uid)))
 			->andWhere($query->expr()->isNull('co.deleted_at'));
 		$stmt = $query->executeQuery();
 		$row = $stmt->fetch();
 		$stmt->closeCursor();
+
+		$owner = explode('/', $row['principal']);
 		if ($row) {
-			return $row['calendaruri'] . '/' . $row['objecturi'];
+			return $owner[count($owner)-1] . '/' . $row['calendaruri'] . '/' . $row['objecturi'];
 		}
 
 		return null;
--- 3rdparty/sabre/dav/lib/CalDAV/Schedule/Plugin.php.org	2024-09-28 19:15:57.635495761 +0200
+++ 3rdparty/sabre/dav/lib/CalDAV/Schedule/Plugin.php	2024-09-28 19:16:16.536325935 +0200
@@ -492,7 +492,7 @@
         $result = $home->getCalendarObjectByUID($uid);
         if ($result) {
             // There was an existing object, we need to update probably.
-            $objectPath = $homePath.'/'.$result;
+            $objectPath = 'calendars/'.$result;
             $objectNode = $this->server->tree->getNodeForPath($objectPath);
             $oldICalendarData = $objectNode->get();
             $currentObject = Reader::read($oldICalendarData);