there are no differnces between 4th gen abs and non abs driveshafts that would affect fitment.
my lude BB4 non-abs has always had abs driveshafts.
the hub nuts should be fully engaged in other words no threads visible on the nut - and the collar can be drifted into the groove on the driveshaft-there is obviously some adjustment where the hub nut can go further than flush with tip of the driveshaft and ive seen a few hub nuts that have one or two threads of the drivehsaft visible once engaged.
there must be an issue with with something other than the driveshaft.......
you know i thought there might be one of the plastic rings off the drivehsaft cv joint that had got stuck in the back of the hub but you say you checked that....
checking the front suspension arm/knuckle/hub against another would be a good place to start - we could get one from a breakers nearby
