After using the APIs from seller register to modify fields like trustPolicy, SecutityPrivacyPolicy, ArchiveId and MerchantName and go back to the seller management admin and save the seller through there, the information of those fields will be set back to the default value.

1. Use the API "Update Seller By Seller Id" and modify the field "trustPolicy" to "AllowEmailSharing" instead of "Default";
2. Wait for the cache time and check using the API "Get Seller Data By Id" to make sure the field was updated.
3. Go to the seller managament UI on the Admin and save the seller through there (no need to change anything);
4. Wait for the cache time and check using the API "Get Seller Data By Id" that the field is back to the default value, in this case "Default";

No workaround for the moment.