Try Deutschepost website too. They own DHL.
GB to me suggests you have a shipment where it enters the UK system directly though with a Royal Mail / PArcelforce / etc. number.
I get the opposite in Germany. Order from Amazon UK, and the UK stuff ships directly from Aachen airport DHL depot with a German DHL tracking number.
edit: oh and it often takes a good 24 hours for DHL tracking site to update with actual tracking info – it often sits for hours as unknown, and then hours as DHL have been informed but it’s not yet collected from the sender (bike24 usually is like that)