[users@httpd] Unable to unset Set-Cookie response header

[Luigi Bellio]

Hi all,

    we are using version 2.4.57 of Apache HTTPd with this configuration
        <VirtualHost *:1080>
            ServerName <OMITTED>:1080
            CustomLog <OMITTED> combined
            ErrorLog <OMITTED>

            DocumentRoot "/usr/local/apache2/conf/extra"

            <Directory /usr/local/apache2/conf/extra>
                Require all granted
            </Directory>

            ErrorDocument 502 <OMITTED>
            ErrorDocument 503 <OMITTED>

            ProxyErrorOverride On

            ProxyPass /favicon.ico !
            ProxyPass /error/ !

   *Header always unset Set-Cookie*

            ProxyPreserveHost On

            ProxyPass / http://<OMITTED>:1080/
            ProxyPassReverse / http://<OMITTED>:1080/
        </VirtualHost>

    and the response header "Set-Cookie" returned by the proxied 
backend is not unset and is returned to client. What is missing?

    Thanks for your support?

    Luigi Bellio.