diff --git a/apps/web/src/components/AppSidebarLayout.tsx b/apps/web/src/components/AppSidebarLayout.tsx
index a3ba76679689..0bc21fbe3f69 100644
--- a/apps/web/src/components/AppSidebarLayout.tsx
+++ b/apps/web/src/components/AppSidebarLayout.tsx
@@ -23,7 +23,7 @@ import {
   resolveSidebarStageFocusRingOffsetClass,
   useSidebarStageBackdropVariant,
 } from "./SidebarStageBackdrop";
-import { useProjects } from "../state/entities";
+import { useProjects, useThreadShells } from "../state/entities";
 import {
   resolveInitialThreadSidebarWidth,
   resolveThreadSidebarMaximumWidth,
@@ -128,11 +128,12 @@ function SidebarControl() {
   );
 }
 
-// Settings swaps the thread sidebar out of the tree. Keep the lightweight
-// project projection subscribed so returning to a draft never renders the
-// zero-project state while the environment snapshot reconnects.
-function ProjectProjectionRetention() {
+// Settings swaps the thread sidebar out of the tree. Keep its lightweight
+// projections subscribed so returning never briefly renders empty project or
+// thread lists while the environment snapshot reconnects.
+function SidebarProjectionRetention() {
   useProjects();
+  useThreadShells();
   return null;
 }
 
@@ -210,7 +211,7 @@ export function AppSidebarLayout({ children }: { children: ReactNode }) {
 
   return (
     <SidebarProvider className="h-dvh! min-h-0!" defaultOpen style={sidebarProviderStyle}>
-      <ProjectProjectionRetention />
+      <SidebarProjectionRetention />
       <Sidebar
         side="left"
         collapsible="offcanvas"
diff --git a/apps/web/src/components/Sidebar.tsx b/apps/web/src/components/Sidebar.tsx
index 0c30a5b6b55e..fb441ccef1d1 100644
--- a/apps/web/src/components/Sidebar.tsx
+++ b/apps/web/src/components/Sidebar.tsx
@@ -3318,9 +3318,28 @@ export default function Sidebar() {
     setShowJumpHints(shouldShowJumpHintsNow);
   }, [shouldShowJumpHintsNow]);
 
+  const listAutoAnimateControllerRef = useRef<ReturnType<typeof autoAnimate> | null>(null);
+  const listAutoAnimateAttachFrameRef = useRef<number | null>(null);
   const attachListAutoAnimateRef = useCallback((node: HTMLUListElement | null) => {
+    if (listAutoAnimateAttachFrameRef.current !== null) {
+      window.cancelAnimationFrame(listAutoAnimateAttachFrameRef.current);
+      listAutoAnimateAttachFrameRef.current = null;
+    }
+    listAutoAnimateControllerRef.current?.destroy?.();
+    listAutoAnimateControllerRef.current = null;
     if (!node) return;
-    autoAnimate(node, { duration: 150, easing: "ease-out" });
+
+    // DndContext installs its accessibility nodes just after this list mounts.
+    // Attach one frame later so those setup mutations are ignored without
+    // canceling auto-animate's initial coordinate tracking.
+    listAutoAnimateAttachFrameRef.current = window.requestAnimationFrame(() => {
+      listAutoAnimateAttachFrameRef.current = null;
+      if (!node.isConnected) return;
+      listAutoAnimateControllerRef.current = autoAnimate(node, {
+        duration: 150,
+        easing: "ease-out",
+      });
+    });
   }, []);
 
   // New thread defaults to the project you're in (active thread's project,