We observed slightly different behavior in SHIP TO ADDRESS of Shipment screen. We have created Transfer type sales order, while creating sales order we have overridden the SHIP TO ADDRESS in Sales Order, then created shipment, now in shipment screen, when we uncheck the "Override Address" checkbox, the address are changing to some default address.
We are using Acumatica 2020R2, build 20.208.0031, without any customizations. Is this default behavior of Acumatica ?
See the below screenshots:

