FIX: Use `visibility: hidden` to hide the buttons to avoid scrolling

app/assets/javascripts/discourse/widgets/topic-timeline.js.es6

@@ -234,7 +234,7 @@ export default createWidget('topic-timeline', {
                               action: 'jumpBottom'
                             })]);
 
-    if (currentUser && !attrs.dockAt) {
+    if (currentUser) {
       const controls = [];
       if (attrs.topic.get('details.can_create_post')) {
         controls.push(this.attach('button', {

app/assets/stylesheets/desktop/topic-timeline.scss

@@ -11,6 +11,11 @@
 
   &.timeline-docked {
     position: absolute;
+
+    .timeline-footer-controls {
+      background-color: yellow;
+      visibility: hidden;
+    }
   }
 
   .topic-timeline {