Backup Errors to FTP

Hi,
after upgrade from 12 to 13 version (10.13.66-22) I have this same problem again:

Whoops\Exception\ErrorException: Argument 1 passed to Touki\FTP\Model\Filesystem::setMtime() must be an instance of DateTime, boolean given, called in /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/WindowsFilesystemFactory.php on line 50 and defined in file /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/Model/Filesystem.php on line 260
Stack trace:

1. Whoops\Exception\ErrorException->() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/Model/Filesystem.php:260
2. Whoops\Run->handleError() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/Model/Filesystem.php:260
3. Touki\FTP\Model\Filesystem->setMtime() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/WindowsFilesystemFactory.php:50
4. Touki\FTP\WindowsFilesystemFactory->build() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/Manager/FTPFilesystemManager.php:162
5. Touki\FTP\Manager\FTPFilesystemManager->findOneBy() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/Manager/FTPFilesystemManager.php:262
6. Touki\FTP\Manager\FTPFilesystemManager->findDirectoryByName() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/Manager/FTPFilesystemManager.php:273
7. Touki\FTP\Manager\FTPFilesystemManager->findDirectoryByDirectory() /var/www/html/admin/modules/backup/vendor/touki/ftp/lib/Touki/FTP/FTP.php:148
8. Touki\FTP\FTP->directoryExists() /var/www/html/admin/modules/backup/functions.inc/class.backup.php:472
9. FreePBX\modules\Backup\Backup->store_backup() /var/www/html/admin/modules/backup/bin/backup.php:148

Backup&Restore module version is 13.0.27.16. I’ve enabled EDGE option but installed version is the latest.
No changes has been made to FTP server configuration lately. This client has one more PBX which runs a backup to the same FTP server with no problem. Backup&Restore module version on this PBX is 13.0.26.

One this I could try is to do a downgrade of Backup module.
Any more suggestion ?

Miro