diff --git a/Data/MySqlRepositories.cs b/Data/MySqlRepositories.cs
index 1bebc4e..8555d8b 100644
--- a/Data/MySqlRepositories.cs
+++ b/Data/MySqlRepositories.cs
@@ -261,7 +261,7 @@ internal sealed class MySqlAttendanceMachineUserRepository : IAttendanceMachineU
         return rows;
     }
 
-    public bool UpsertMachineUser(string machineId, string serialNumber, string employeeName, out string error)
+    public bool UpsertMachineUser(string machineId, string serialNumber, string employeeName, string updatedBy, out string error)
     {
         error = "";
         if (!_factory.TryBuildConnectionString(out var cs, out error))
@@ -271,11 +271,12 @@ internal sealed class MySqlAttendanceMachineUserRepository : IAttendanceMachineU
             using var conn = new MySqlConnection(cs);
             conn.Open();
             using var cmd = new MySqlCommand(
-                "REPLACE INTO attendance_machine_user (machine_id,serial_number,employee_name,is_deleted,is_deletion_requested,updated_at) " +
-                "VALUES (@machine_id,@serial_number,@employee_name,0,0,NOW())", conn);
+                "REPLACE INTO attendance_machine_user (machine_id,serial_number,employee_name,is_deleted,is_deletion_requested,updated_by,updated_at) " +
+                "VALUES (@machine_id,@serial_number,@employee_name,0,0,@updated_by,NOW())", conn);
             cmd.Parameters.AddWithValue("@machine_id", machineId ?? "");
             cmd.Parameters.AddWithValue("@serial_number", serialNumber ?? "");
             cmd.Parameters.AddWithValue("@employee_name", employeeName ?? "");
+            cmd.Parameters.AddWithValue("@updated_by", string.IsNullOrWhiteSpace(updatedBy) ? "hikvision-service" : updatedBy.Trim());
             cmd.ExecuteNonQuery();
             return true;
         }
@@ -320,11 +321,26 @@ internal sealed class MySqlAttendanceMachineFaceTemplateRepository : IAttendance
             using var conn = new MySqlConnection(cs);
             conn.Open();
 
+            // Skip rewrite when an active non-empty template is already stored for this employee.
             using (var existsCmd = new MySqlCommand(
-                       "SELECT 1 FROM attendance_machine_face_templates WHERE serial_no=@serial_no LIMIT 1", conn))
+                       "SELECT 1 FROM attendance_machine_face_templates " +
+                       "WHERE serial_no=@serial_no AND is_active=1 AND template IS NOT NULL AND LENGTH(template)>0 " +
+                       "LIMIT 1", conn))
             {
                 existsCmd.Parameters.AddWithValue("@serial_no", serialNo ?? "");
-                createdNew = existsCmd.ExecuteScalar() == null;
+                if (existsCmd.ExecuteScalar() != null)
+                {
+                    createdNew = false;
+                    return true; // already present — do not UPDATE / re-INSERT
+                }
+            }
+
+            // Insert new, or fill/replace an empty/inactive row for the same serial.
+            using (var existsAnyCmd = new MySqlCommand(
+                       "SELECT 1 FROM attendance_machine_face_templates WHERE serial_no=@serial_no LIMIT 1", conn))
+            {
+                existsAnyCmd.Parameters.AddWithValue("@serial_no", serialNo ?? "");
+                createdNew = existsAnyCmd.ExecuteScalar() == null;
             }
 
             if (createdNew)
@@ -348,6 +364,7 @@ internal sealed class MySqlAttendanceMachineFaceTemplateRepository : IAttendance
                 update.Parameters.AddWithValue("@created_date", createdDate);
                 update.Parameters.AddWithValue("@is_active", isActive ? 1 : 0);
                 update.ExecuteNonQuery();
+                createdNew = true; // treat fill of empty row as a new save for caller logging
             }
 
             // Best-effort source metadata update for schemas that include these columns.