Due to questions arising over Cold procs recently, I did a little testing with the Glaxion Vandal, and since I hadn't really used it in a while, decided to run some missions with it, only to notice that it wasn't hitting multiple enemies in a row despite using Primed Shred. Previously, the radial effect on the weapon would appear at the end of the beam regardless of how many enemies it hit along the way. Now however, it appears that the beam just doesn't take Punch Through at all, stops at the first thing it hits, and grants the radial at that point.
It also now appears that Punch Through doesn't get a listing in the stats screen, which potentially gives the impression that this is intentional, but if it were intentional, there would be patch notes, which there aren't any that I've found.