If I cancel a shipment in ShippingEasy (that originated in my WooCommerce store), the tracking number and status in my WooCommerce store do not change. Minimally, I would expect the tracking number to be deleted and an email sent to customer that this shipping label has been cancelled (the latter would be nice to have).
In addition, when I create a duplicate shipment for this same WooCommerce order, it should update the WooCommerce order with the new tracking number and send an email to the customer as is done when the initial tracking number was generated.
Essentially when you cancel a shipment in SE, the corresponding tracking # should be deleted in WooCommerce. Similarly a new tracking number should update WooCommerce.
All this needs to be done manually today.
All of this is subject to WooCommerce's API limits.