diff --git a/app/mobile/engagement/page.tsx b/app/mobile/engagement/page.tsx
index f682f75..6008c67 100644
--- a/app/mobile/engagement/page.tsx
+++ b/app/mobile/engagement/page.tsx
@@ -172,6 +172,38 @@ export default function MobileEngagementPage() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [sortKey]);
 
+  // D-04 fallback: the mobile shell's <main> is overflow-y-auto, so Next.js's
+  // built-in scrollRestoration (which targets window) doesn't help. Persist the
+  // inner scroll position across navigations via sessionStorage so back from
+  // /mobile/engagement/[userId] restores the row the user tapped.
+  const restoredScrollRef = useRef(false);
+  useEffect(() => {
+    const main = document.querySelector('main');
+    if (!main) return;
+    let raf = 0;
+    const onScroll = () => {
+      if (raf) return;
+      raf = requestAnimationFrame(() => {
+        raf = 0;
+        sessionStorage.setItem('mobile-engagement-list-scroll', String(main.scrollTop));
+      });
+    };
+    main.addEventListener('scroll', onScroll, { passive: true });
+    return () => {
+      main.removeEventListener('scroll', onScroll);
+      if (raf) cancelAnimationFrame(raf);
+    };
+  }, []);
+  useEffect(() => {
+    if (restoredScrollRef.current) return;
+    if (usersLoading || users.length === 0) return;
+    const main = document.querySelector('main');
+    if (!main) return;
+    const saved = sessionStorage.getItem('mobile-engagement-list-scroll');
+    if (saved) main.scrollTop = parseInt(saved, 10);
+    restoredScrollRef.current = true;
+  }, [usersLoading, users.length]);
+
   // IntersectionObserver — D-18 (mirrors Phase 4/6 pattern, rootMargin '200px')
   const sentinelRef = useRef<HTMLDivElement | null>(null);
   useEffect(() => {