diff --git a/web/src/book-detail.ts b/web/src/book-detail.ts
index bb35c84f..b1f48d76 100644
--- a/web/src/book-detail.ts
+++ b/web/src/book-detail.ts
@@ -210,8 +210,20 @@ Alpine.data("bookDetail", () => {
             headers: { Authorization: getAuthHeader() },
           }),
         ]);
-        const notes = noteResp.ok ? await noteResp.json() : [];
-        const highlights = hlResp.ok ? await hlResp.json() : [];
+        // A partial failure must not read as "no annotations": a failed
+        // endpoint used to be published as an empty list, silently wiping
+        // that kind from the banner while the other kind stayed (found
+        // auditing the app's fetch-wipe fix, bookhoard-app 07bbb4c).
+        // Keep the previous rows; the next banner open retries.
+        if (!noteResp.ok || !hlResp.ok) {
+          console.warn(
+            `banner annotation load failed ` +
+              `(notes ${noteResp.status}, highlights ${hlResp.status}) — keeping previous`,
+          );
+          return;
+        }
+        const notes = await noteResp.json();
+        const highlights = await hlResp.json();
         const built = buildAnnotationRows(notes, highlights);
         this.bannerRows = built.rows;
         this.bannerSources = built.sources;