Free SSL certificate not working on Android?

Question

Android

Good evening, I installed the certificate according to this instruction https://habrahabr.ru/post/249529/
Everything would be fine, but from mobile devices it says that the connection is insecure
My Apache config

<IfModule mod_ssl.c>
   <VirtualHost _default_:443>
       ServerAdmin [email protected]
       ServerName ***
       ServerAlias ***
       DocumentRoot /var/www/html/public
     <Directory />
      Options FollowSymLinks
      AllowOverride None
  </Directory>
  <Directory /var/www/html>
      AllowOverride All
  </Directory>
       ErrorLog ${APACHE_LOG_DIR}/error.log
       CustomLog ${APACHE_LOG_DIR}/access.log combined
       SSLEngine on
       SSLCertificateFile /etc/apache2/serfs/2_***.crt
     SSLCertificateKeyFile /etc/apache2/serfs/3_***.key
       <FilesMatch "\.(cgi|shtml|phtml|php)$">
                       SSLOptions +StdEnvVars
       </FilesMatch>
       <Directory /usr/lib/cgi-bin>
                       SSLOptions +StdEnvVars
       </Directory>
       BrowserMatch "MSIE [2-6]" \
                       nokeepalive ssl-unclean-shutdown \
                       downgrade-1.0 force-response-1.0
       BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown
   </VirtualHost>
</IfModule>

Answer 1

Apache config has nothing to do with it. The CA that issued the certificate is not on the list of trusted root certificates. As a rule, this is how they react either to corporate CAs or to "unreliable" ones. A certificate issued by Thawte or Comodo will not be responded to in this way.

Answer 2

"cutlets separately, flies should be separate" (c)
fasten a free certificate from trusted certification authorities - that's all ..
from the same - StartCom Ltd

Answer 3

Just checked, everything works. It was wosign