Error CSS style withing installation process

[neerro]

Hi there!
Within my installation process Setup without Docker on Step.5, I met the next issue (it seems occurs due to CSS style).
Is anybody can help me to fix this issue?

My server configuration:
OS Ubuntu 22.04
Apache v2.4.53
PHP v7.4.29
MariaDB v10.6.7
Instance directory rules:
chown -R www-data:www-data
chmod -R 775

[Kovah]

If you see this you did not properly configure your web server. It must point its docroot to the public directory in the LinkAce folder, not the LinkAce folder itself.

[neerro]

@Kovah, thanks a lot for your prompt reply.
Yes, definitely, the issue was in it. I've changed docroot path to the public and everything worked well.

But during of app usage, unfortunately I've met another one issue (see the picture below and my reproducing steps).
Step 1. From dashboard panel, I have gone to settings, made some changes.
Step 2. Went to the end of page to Save Settings
Step 3. After I put on the button Save Settings the window with message has appeared on address mydomane.name/fetch/update-check
Finally, all settings are safe, but the app doesn't back to the settings window.
Is this also something wrong with my settings wherefore I see this bug?
Please, support me with this issue too.

[martadinata666]

it works correctly in my system, this is the result on step three

My apache conf

<VirtualHost *:443>
    Protocols h2 http/1.1
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html/public

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem
    SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key
    
    <Directory "/var/www/html/">
        AllowOverride All
        Require all granted
    </Directory>

    <FilesMatch "\.php$">
        SetHandler "proxy:fcgi://localhost:9000/"
        SSLOptions +StdEnvVars
    </FilesMatch>
     
    <Files ~ "^.ht">
        Order allow,deny
        Deny from all
    </Files>

</VirtualHost>

[neerro]

it works correctly in my system, this is the result on step three

Huh! Maybe I did something wrong in my settings? As I haven't any extraordinary in my apache configuration, everything as usually.
And in principle I would to know, what does it mean this error? What kind of issue it could be?