Since 1/1/21, the treatment depends on whether you’re selling to EU customers from the UK, or from any stocks that you’re keeping in the EU.
From your question, I’m assuming that the sale is being made in the UK. The transaction can be zero-rated (for UK VAT purposes) because you’re immediately exporting the goods. Import VAT/duty would normally be charged to the importer (your customer), although through DDP you’re bearing the cost of this in order to avoid the customer incurring unexpected charges. You can’t reclaim this import VAT because it’s the VAT on your customer’s purchase.
But, in these circumstances, I can’t see why you would be required to charge VAT in the foreign country. Your supply has been made in the UK and VAT has been accounted on the import. So it may be that you’re currently overpaying VAT through your foreign VAT registrations?
Alternatively, if you held stocks of goods in the EU, you could make the sales from there. It would then be correct to charge foreign VAT to the customers. You would be the importer of the goods if you bought them into your EU stocks from the UK – so you could recover the import VAT on your foreign VAT return, as it would be the VAT on your purchase.
But there are further rule changes planned from 1/7/21 which may impact on you.