From the DHL tracking FAQ: https://www.dhl.com/en/express/tracking/tracking_faq.html
When I track my international DHL Express shipments, why do I sometimes get information for a shipment that is not going to the intended destination?
DHL periodically recycles shipment waybill numbers for operational reasons. Occasionally this results in information being in our systems at the same time for two shipments travelling under the same waybill number. DHL is working hard to eliminate these occurrences however, in the meantime, please be assured that while this information may be confusing, your physical shipment will be heading to its correct destination and be receiving the same careful attention as every other shipment in our network.