The help2.js script contains a function that triggers a contact attempt to piwik.documentfoundation.org when the help is opened with Chrome or Edge, even though they are in file mode. FireFox does not attempt to connect.
Since an "offline help" should be completely offline, I think this is a bug.

This may also be the reason for bug ID 140983


This is the part of the script help2.js: 
...
// Test, if we are online
if (document.body.getElementsByTagName('meta')) {
    var _paq = _paq || [];
    /* tracker methods like "setCustomDimension" should be called before "trackPageView" */
    _paq.push(['disableCookies']);
    _paq.push(['trackPageView']);
    _paq.push(['enableLinkTracking']);
    (function() {
    var u="//piwik.documentfoundation.org/";
    _paq.push(['setTrackerUrl', u+'piwik.php']);
    _paq.push(['setSiteId', '68']);
    var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
    g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'piwik.js'; s.parentNode.insertBefore(g,s);
    })();
    var system = getParameterByName("System");
} else {
    var system = getSystem();
}
...

Discovered in
Version LO 7.4.7.2 x64 Community
with Hilfe 7.4 (German) (LibreOffice_7.4.7_Win_x64_helppack_de.msi)
but also found in Hilfe 7.5 (LibreOffice_7.5.6_Win_x64_helppack_de.msi)