diff --git a/app/app/static/app.js b/app/app/static/app.js
index 7bd6101..fb9020e 100644
--- a/app/app/static/app.js
+++ b/app/app/static/app.js
@@ -123,6 +123,13 @@ function groupRecordsByTeacher(records) {
   });
 }
 
+function initializeTeacherGroupCollapse(records) {
+  const groups = groupRecordsByTeacher(records);
+  collapsedTeacherGroups = groups.length > 1
+    ? new Set(groups.map((group) => group.teacher))
+    : new Set();
+}
+
 function getDisplayRecord(row) {
   return correctedRecords.get(row._recordKey) || row;
 }
@@ -811,6 +818,9 @@ async function queryRecords(query, options = {}) {
       _recordIndex: currentRecordPage.offset + index,
       _recordKey: makeRecordKey(row, currentRecordPage.offset + index),
     }));
+    if (options.reset !== false) {
+      initializeTeacherGroupCollapse(currentRecords);
+    }
     recordRows.innerHTML = renderGroupedRecords(currentRecords);
   } catch (error) {
     recordRows.innerHTML = `<tr><td colspan="${RECORD_TABLE_COLUMN_COUNT}" class="empty">查询失败：${escapeHtml(error.message)}</td></tr>`;