Please see below guidance from DEFRA:
This is for those who use TRACES NT for the import of live animals from outside the EU
Thank you for registering and migrating to TRACES NT.
We have been notified that BCPs are receiving some CHED-As with box I.28 – ‘Transporter’ not completed.
Please make sure that you complete this box, otherwise the necessary link to HMRC systems will not be established and your consignment will be delayed. We do realise that using a new system can lead to errors but unfortunately this is having a profound knock-on effect.
Note that the requirement for this information has not changed - even though TRACES NT does not prompt you to complete box 1.28 before submission in the way that TRACES Classic did, the requirement remains.
For more detail and further guidance please see the attached:
The Imports and Exports Team
Department for Environment, Food and Rural Affairs (Defra)