If you have got an A1-A3 certificate from outside the Netherlands, it's now possible to apply for a Dutch A1-A3 certificate at the RDW.
However your drone license is valid in every EU country (including Norway, Iceland and Switzerland), there isn't an European database for authorities to verify certificates from different European countries. For the A2 certificate is an upgrade of A1-A3, it was not possible to check if you have a valid certificate and therefore A2 could not be issued.
However, in the Netherlands you are able to manually apply for a Dutch A1-A3 certificate at the RDW. This is only for Dutch citizens, on the moment, with A1-A3 certificate obtained in another EASA member state.
There should already have been an European database in the first place, but there are more things that need to be fixed. We hope it will be possible for foreigners to apply for certification in the Netherlands very soon. Then our EU Drone License will be available to order.