Your team ingests a clickstream from Pub/Sub into a streaming Dataflow pipeline that computes per-user session activity aggregated into 10-minute fixed windows. Mobile clients frequently buffer events and send them minutes after they occurred, sometimes well after the window has fired. Business analysts complain that late-arriving events are silently dropped, producing undercounted metrics. You must ensure late events still update the correct window's results while keeping the pipeline emitting timely initial results. What should you do?