fix incorrect sticking in user profile page

src/components/timeline/timeline.scss

@@ -10,7 +10,7 @@
   }
 
   .conversation-heading {
-    top: calc(var(--__panel-heading-height) * 2);
+    top: calc(var(--__panel-heading-height) * var(--currentPanelStack, 2));
     z-index: 1;
   }
 

src/components/user_profile/user_profile.vue

@@ -142,6 +142,9 @@
   flex: 2;
   flex-basis: 500px;
 
+  // No sticky header on user profile
+  --currentPanelStack: 1;
+
   .user-profile-fields {
     margin: 0 0.5em;