Users can delete the open files in external storage

Nextcloud version: 13.0.4
Operating system and version :Slackware 14.2
Apache or nginx version: Apache 2.4.33
PHP version: 7.2.4

Hi there!
My NC has a shared folder with 123.doc file. This folder a samba resource. I opening the file 123.doc in Collabora Office for edit. At a edit time the other NC user deleted this file. Why not worked locking? Log file have not lines about locking errors.

I have in config.php
‘filelocking.enabled’ => true,
‘memcache.local’ => ‘\\OC\\Memcache\\Redis’,
‘memcache.locking’ => ‘\\OC\\Memcache\\Redis’,
‘redis’ =>
array (
‘host’ => ‘localhost’,
‘port’ => 6379,

and in samba.conf
locking = yes