li id="menu-item-20" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home menu-item-20">
<a href="https://www.gollnow-bau.de/">
<i class="fa-home fa"></i>
<span class="fontawesome-text"></span>
</a>
</li>
ok here are the differents at runtime
<li id="menu-item-78" class="fa-share-alt-square menu-item menu-item-type-post_type menu-…tem-object-page menu-item-has-children dropdown menu-item-78">
<a href="https://www.gollnow-bau.de/dienstleistungen"></a>
<ul class="dropdown-menu">
<li id="menu-item-79" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-79"></li>
<li id="menu-item-81" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-81"></li>
</ul>
</li>
seems for me that the fontawesome attribute at beginning of the class definition
class="fa-share-alt-square menu-item
sets the menuitem out of place