NC 17.0.3 issue with first cyrillic symbol in file name (Office 2003 mime types)

Nextcloud version: 17.0.3
Operating system and version: Ubuntu 18.04.4 LTS
Apache or nginx version: Apache/2.4.29
PHP version: 7.2.24
MySQL version: 10.1.44

The issue you are facing:
When uploading DOC/PPT/XLS files with first cyrillic symbol in the name - first word of file name dissapeared from GUI. When renaming DOC/PPT/XLS and setting firs name symbol in cyrillic - first word of file name dissapeared from GUI. Affected only DOC/PPT/XLS, with zip/pdf/txt/docx/pptx/xlsx everything is ok. Bug affected by mime-type. When renaming txt file to doc and setting first cyrillic symbol in the name - bug is not heppend. On the disk files names are OK (as original).

Video with issue: https://cloud.uhe.gov.ua/index.php/s/Fb45ARNjiRKF2ap
Password: NextcloudBug

Is this the first time you’ve seen this error? Yes

Steps to replicate it:

  1. Create doc file. Name it “Тест file.doc”
  2. Upload to NC server.
  3. Press F5. File name will be “file.doc”

The output of your Nextcloud log in Admin > Logging: no errors affected by this issue

The output of your config.php file:

<?php
$CONFIG = array (
  'apps_paths' =>
  array (
    0 =>
    array (
      'path' => '/var/www/nextcloud/apps',
      'url' => '/apps',
      'writable' => true,
    ),
  ),
  'supportedDatabases' =>
  array (
    0 => 'mysql',
  ),
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'memcache.local' => '\\OC\\Memcache\\Redis',
  'redis' =>
  array (
    'host' => '127.0.0.1',
    'port' => '6379',
  ),
  'instanceid' => 'sensetivedata',
  'passwordsalt' => 'sensetivedata',
  'secret' => 'sensetivedata',
  'trusted_domains' =>
  array (
    0 => 'sensetivedata',
    1 => 'sensetivedata',
    2 => 'sensetivedata',
  ),
  'default_language' => 'uk',
  'datadirectory' => '/media/ncdata/data',
  'dbtype' => 'mysql',
  'version' => '17.0.3.1',
  'overwrite.cli.url' => 'sensetivedata',
  'dbname' => 'sensetivedata',
  'dbhost' => '127.0.0.1',
  'dbport' => '3306',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'sensetivedata',
  'dbpassword' => 'sensetivedata',
  'installed' => true,
  'ldapIgnoreNamingRules' => false,
  'ldapProviderFactory' => 'OCA\\User_LDAP\\LDAPProviderFactory',
  'maintenance' => false,
  'twofactor_enforced' => 'false',
  'twofactor_enforced_groups' =>
  array (
  ),
  'twofactor_enforced_excluded_groups' =>
  array (
  ),
  'loglevel' => 2,
  'theme' => '',
  'updater.release.channel' => 'stable',
  'onlyoffice' =>
  array (
    'verify_peer_off' => true,
  ),
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'mail_from_address' => 'sensetivedata',
  'mail_domain' => 'sensetivedata',
  'mail_smtphost' => 'sensetivedata',
  'mail_smtpport' => '25',
);

how are locales set on your account, on your nc-instance and on your server-machine?

I don’t think that problem in locales. - becouse there is no problem with PDF files.
On the server locale set to en_US.UTF-8. On NC account I’m trying to switch between russian, ukrainian and english language - nothing changes, issue still appears. On the instance default_language is uk.

NC working ok with cyrillic symbols in account First Name / Last Name fields, and in other files names. Server displays cyrillic file names normaly. So I think problem in something other.