Hi @Seller_1q7SEetEljmRJ,

Are/were you using a partnered carrier? As noted on the Send shipments to Amazon Warehousing and Distribution (AWD): Tracking details help page:

The Tracking details is currently only applicable for all Small parcel deliveries (SPD) and only for Amazon Partnered Carrier in case of less than truckload or full truckload (LTL) shipments. For LTL Partnered carrier shipments, we’ll generate the carrier tracking ID information for you.

This should be the answer you're looking for, but let me know if you still need help!

Topher