Why are my Amazon orders showing "not found" after changing my password?

This should help:

Alternatively, you can work around the problem by using the “Amazon - by tracking link” option. If you go to Amazon’s “Your Orders” page in Safari, you can use the Share button and then choose “Add to Deliveries” for a list of shipments you can add. Or you can copy the link of any “Track package” button on the “Your Orders” page and paste it into Deliveries. The “Amazon - by tracking link” option will track a specific shipment, rather than the whole order.