Expected behavior font awesome icons are displayed correctly

Actual behavior If I load the html file locally in the browser, all the icons are displayed correctly (see attached "screenshot2.png" file). If I load the page from an http server, the class list is displayed next to some of the icons (see attached "screenshot.png"). For some reason, the "fas fa-sort-down" icon is displayed correctly, while the "fas fa-sort" icon is displayed with the "fas fa-sort sortable me-1" text next to it. To be noted that the actual class list is "fas fa-sort me-1 sortable", while the text displayed is "fas fa-sort sortable me-1", i.e. the sortable and me-1 classes are in a different position. I have cleared the cache and performed a hard reload but the problem persist. Opening the developer tools, I see no errors. If I use the same class list in all the icons, only the first one is displayed correctly.

Resources (screenshots, code snippets etc.) The relevant html is:

<th class="fw-bold" scope="col"><a onclick='sortOrderTable(event)'><i class="fas fa-sort-down text-primary me-1 sortable"></i></a>Id</th>
<th class="fw-bold" scope="col"><a onclick='sortOrderTable(event)'><i class="fas fa-sort me-1 sortable"></i></a>Processor</th>