Error 500 - after 240s of file upload. With what can be connected?

Question

PHP

Given: IIS 7, php 8
The site works, there are no problems. Because Windows hosting IIS uses web.config.
It is required to upload a 700Mb file via the input field. There were no problems with the 58Mb file when loading, no errors.
Actually the web.config itself (a lot of things because laravel - I set the restrictions on the weight and length of the download, respectively)

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.web>
        <httpRuntime maxRequestLength="400000000" executionTimeout="900000" />
  </system.web>
  <system.webServer>
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="2147483648" />
      </requestFiltering>
    </security>
    <staticContent>
            <mimeMap fileExtension=".mp4" mimeType="video/mp4" />
            <mimeMap fileExtension=".m4v" mimeType="video/m4v" />
    </staticContent>
        <defaultDocument>
            <files>
                <clear />
                <add value="index.php" />
                <add value="default.aspx" />
                <add value="Default.htm" />
                <add value="Default.asp" />
                <add value="index.htm" />
                <add value="index.html" />
            </files>
        </defaultDocument>
        <rewrite>
            <rules>
                <rule name="Импортированное правило 1" stopProcessing="true">
                    <match url="^" ignoreCase="false" />
                    <conditions logicalGrouping="MatchAll">
                        <add input="{HTTP_AUTHORIZATION}" ignoreCase="false" />
                        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />
                        <add input="{URL}" pattern="(.+)/$" ignoreCase="false" />
                    </conditions>
                    <action type="Redirect" url="{C:1}" redirectType="Permanent" />
                </rule>
                <rule name="Импортированное правило 2" stopProcessing="true">
                    <match url="^" ignoreCase="false" />
                    <conditions logicalGrouping="MatchAll">
                        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />
                        <add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
                    </conditions>
                    <action type="Rewrite" url="index.php" />
                </rule>
            </rules>
        </rewrite>
        <handlers>
            <remove name="PHP_via_FastCGI" />
            <remove name="PHP53_via_FastCGI" />
            <remove name="PHP_via_FastCGI1" />
            <add name="PHP_via_FastCGI" path="*.php" verb="GET,HEAD,POST" modules="FastCgiModule" scriptProcessor="C:\php\php-cgi.exe" resourceType="Either" requireAccess="Script" />
        </handlers>
    </system.webServer>
</configuration>

Further, what is important - php.ini is also configured as it should

upload_max_filesize = 2000M
max_file_uploads = 2000
post_max_size = 8000M
max_execution_time = 900000
max_input_time = 900000
memory_limit = 10000M

And just to be sure, on the page with the code, I additionally add this

ini_set('post_max_size', '8000M');
        ini_set('upload_max_filesize', '2000M');
        ini_set('max_execution_time', '900000');
        ini_set('max_input_time', '900000');

Please explain what is wrong with all this and why it resets my connection. On a mobile phone, an error 500 pops up on a PC. Connection reset. ERR_CONNECTION_RESET

Answer 1

Start by looking at the logs on the server.
The 500 error must be logged somehow.