diff --git a/.lane/memory/packages/ui/src/components/scroll-view/scroll-view.tsx/01M5JPN2QNMG751NXC43TCM3SR-a-quiet-period-must-end-a-sc.md b/.lane/memory/packages/ui/src/components/scroll-view/scroll-view.tsx/01M5JPN2QNMG751NXC43TCM3SR-a-quiet-period-must-end-a-sc.md
new file mode 100644
index 00000000..b5bb09d1
--- /dev/null
+++ b/.lane/memory/packages/ui/src/components/scroll-view/scroll-view.tsx/01M5JPN2QNMG751NXC43TCM3SR-a-quiet-period-must-end-a-sc.md
@@ -0,0 +1,12 @@
+---
+id: 01M5JPN2QNMG751NXC43TCM3SR
+anchor: '@file'
+created: 2026-10-22T21:00:43Z
+norm: '1'
+sig: e0cbdab303939db3
+body_hash: 6885f9b9dd17486d
+raw_hash: 38eb59c30e3b5a2c
+lines: 1-374
+---
+
+a quiet period must end a scroll; browsers send no scrollend when they clamp scrollTop after content shrinks
diff --git a/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M53FDJQ4C0BGDGXNAY5GK09T-a-file-block-s-cache-key-inc.md b/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M53FDJQ4C0BGDGXNAY5GK09T-a-file-block-s-cache-key-inc.md
index e99a0f9c..3ba42a06 100644
--- a/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M53FDJQ4C0BGDGXNAY5GK09T-a-file-block-s-cache-key-inc.md
+++ b/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M53FDJQ4C0BGDGXNAY5GK09T-a-file-block-s-cache-key-inc.md
@@ -4,9 +4,9 @@ anchor: '@file'
 created: 2026-10-16T23:05:41Z
 norm: '1'
 sig: ce515648b5bedef2
-body_hash: a984910f8f8a9cdc
-raw_hash: c0f95564f75550a7
-vouched: 2026-10-22T20:42:40Z
+body_hash: 3696028d4b1ada45
+raw_hash: 67b90ab8452ae3e8
+vouched: 2026-10-22T21:00:46Z
 lines: 1-912
 ---
 
diff --git a/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M5JPN2P38553WJGVMF742JC7-every-render-with-an-unparse.md b/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M5JPN2P38553WJGVMF742JC7-every-render-with-an-unparse.md
new file mode 100644
index 00000000..a7f73aa3
--- /dev/null
+++ b/.lane/memory/packages/ui/src/components/timeline/layout.ts/01M5JPN2P38553WJGVMF742JC7-every-render-with-an-unparse.md
@@ -0,0 +1,12 @@
+---
+id: 01M5JPN2P38553WJGVMF742JC7
+anchor: function textBlocks
+created: 2026-10-22T21:00:43Z
+norm: '1'
+sig: 501d68b5e67bcf4e
+body_hash: fd0944277f6addb6
+raw_hash: 64f19e54a7a5b9a1
+lines: 451-496
+---
+
+every render with an unparsed chunk must queue its job, even one already in flight, or a cancelled effect leaves the old text on screen
diff --git a/packages/ui/src/components/scroll-view/scroll-view.tsx b/packages/ui/src/components/scroll-view/scroll-view.tsx
index efd4c3b2..07b03705 100644
--- a/packages/ui/src/components/scroll-view/scroll-view.tsx
+++ b/packages/ui/src/components/scroll-view/scroll-view.tsx
@@ -15,6 +15,7 @@ import { cn } from "../../lib/utils";
 
 const EMPTY: scroll.Frame = { items: [], total: 0 };
 const INTENT = 500;
+const QUIET = 200;
 
 /** Imperative handle exposed via ref. */
 type ScrollViewHandle = {
@@ -244,14 +245,20 @@ function ScrollView(
 				project.current(true);
 			});
 		};
+		// Browsers send no scrollend when they clamp scrollTop after content shrinks, so a
+		// quiet period also ends a scroll; otherwise onScrollEnd never runs.
+		let quiet: ReturnType<typeof setTimeout> | undefined;
 		let onscroll = () => {
 			if (!scrolling.current) {
 				scrolling.current = true;
 				started.current?.();
 			}
+			clearTimeout(quiet);
+			quiet = setTimeout(done, QUIET);
 			schedule();
 		};
 		let done = () => {
+			clearTimeout(quiet);
 			if (!scrolling.current) return;
 			scrolling.current = false;
 			settled.current?.();
@@ -294,6 +301,7 @@ function ScrollView(
 
 		return () => {
 			active = false;
+			clearTimeout(quiet);
 			observer.disconnect();
 			el.removeEventListener("scroll", onscroll);
 			el.removeEventListener("scrollend", done);
diff --git a/packages/ui/src/components/timeline/layout.ts b/packages/ui/src/components/timeline/layout.ts
index 9fc92600..8badb432 100644
--- a/packages/ui/src/components/timeline/layout.ts
+++ b/packages/ui/src/components/timeline/layout.ts
@@ -476,7 +476,9 @@ function textBlocks(
 		return hit;
 	}
 
-	if (!parsed.get(k)?.promise && !seen.has(k) && (!streaming || !stream.has(slot))) {
+	// Queue in-flight parses too: start() reuses their promise, and this render's tick must not
+	// depend on an earlier render whose effect may already have been cancelled.
+	if (!seen.has(k)) {
 		jobs.push({ key: k, raw: chunk.raw, sig, mentions, plan, compact, streaming, slot });
 		seen.add(k);
 	}