It's absolutely baffling. I've been looking into it for cheeses and ales, so many UK producers flat out say "We only ship within the UK" even though the cost of shipping is covered by the buyer and it would cost nothing, not even extra paperwork, to ship to the EU (for now).
Bonded warehouses exist for a reason. Internationally shipping alcohol or (tobacco) is genuinely complicated even within the eu. Cheese probably just a perishable pain to post far.