Of course, the article paints the worst possible picture.
You have to read through to almost the end before you realise they're talking about an apparent 'blip' and that freight volumes were back to their normal levels since the start of February

And that: “A unique combination of factors, including stockpiling last year, Covid lockdowns across Europe and businesses adjusting to our new trading relationship, made it inevitable that exports to the EU would be lower this January than last,” said a spokesperson for the department (DEFRA).