Yes this is because of Brexit, but it seems to me that the issue is the EU. We have a parcel stuck in a warehouse in Germany for over 6 weeks now - all customs paperwork was filled in correctly but for some reason it is the German government who wont let the parcel in, no issues on the export side at all, seems to be importing to EU thats the issue and I dont understand why its any different than for example if an item was sent to the EU from the US, or Australia etc. Its madness. Also we just had 3 parcels sent back to the UK from the EU, again all customs paperwork was completed and 3 copies of the commercial invoice attached all as they should be. Why were they sent back? nobody knows. If I didnāt know any better I could only assume that the EU is trying to be obstructive for parcels from the UK.
This is what your government charges for importing parcels, because of Brexit you didnāt pay UK VAT which would have been due in the old system, in your case UK vat on those goods would have been an additional Ā£38.44 (or in Euros, 44.49) so yeah you are out 13.51 Euros because of a hefty import charge your country charges