I have not had that happen to me.
To attach the points I run a glue stick (from a glue gun) through a candle flame, and wipe the melted glue onto the nail shaft. Then when I think I have enough on there, I run the nail with glue on it thru the flame to melt it all again....and slide it into position, hold for a few seconds and I'm done. Some glue will squeeze out near the nail head, but with a firm pressure I can get the nail to seat properly. Then I just peel off the extra glue. My predrilled hole in the shaft is just a bit larger than the nail shaft. On some of my nail heads, I sanded a flat spot along the whole nail shaft first, with the intention of making a good glue joint.
I noticed that some of the duplex heads do not have the nail shaft centered to the head, this results in a point that is not in-line with the arrrow shaft. So, after initial placement into the arrow shaft, if there needs to be an adjusment, I hold the point into the candle flame and heat it up a bit, just enough to allow me to twist the nail to the best position.
To address the little "lip" that is formed when the duplex head is a larger diameter than the shaft, I simply rotate the shaft on my sander to smooth down the "lip" without cutting into the shaft material. This also slightly tapers the actual head of the nail (the part that sits against the arrow shaft) and makes a nice smooth transition between duplex nail head and shaft which offers no resistance when in the target. Unlike my field points which always seem to need to be pulled hard out of my club's targets (and often get eaten by the 3D targets), the duplex arrows slip out easily.
Short question Agd68, but a long answer....lol