asset/scss/global/_omeka.scss

@@ -145,7 +145,7 @@
         background-color: scale-color($white, $alpha: 90%);
       }
       &.is-at-top {
-        margin-top: 0;
+        margin-top: 0 !important;
       }
     }
   }

view/omeka/site/page/show.phtml

@@ -64,7 +64,7 @@ if ($activePage):
 <?php if ($activePage): ?>
     <?php if ($this->displayNavigation && $activePage['page']->hasPages()): ?>
     <nav class="sub-menu wide" data-sticky-container>
-        <div class="sticky" data-sticky data-anchor="blocks">
+        <div class="no-sticky" no-data-sticky no-data-anchor="blocks">
             <?php echo $nav->menu()->setUlClass('horizontal menu')->renderSubMenu(); ?>
         </div>
     </nav>