There was absolutely no border issue until Cameron called and lost a extremely ill-advised referendum. The issue of the border was once hundred percent instigated by the UK. Border arrangements between nations and large trading blocs can't be mucked about with just because one country decides it wants to change things. There are plenty of countries watching to make sure that the UK, the country causing all the problems lest we forget, doesn't get advantages that they can't have apropos of border arrangements. If you think that the EU is being awkward about this, it's worth remembering that we have decided to be quite a small country that's cutting itself adrift. You ain't seen nuthin' yet. Just wait and see how awkward it's going to be making trade deals with the world's protectionist giants once we're out. They're not sitting out there waiting to do us any favours either.