I have found two issues with pnb snapping. The first has only been happening since the last update.(the real update, not the hotfixes) It happens when placing pnbs, on a non-pnb surface, with snapping activated. So I have a angled beam in my hand, and it passes over a placed vertical beam, and snaps beside the placed beam and I keep moving without placing. The beam is then vertical, or in whatever position the placed beam is in, not back to the angled position it was originally in. I hope ya'll get the context lol, it was more than a little difficult to explain.
The second problem I have noticed for a long time, and isn't as annoying. When placing a pnb, with snapping enabled, it doesn't work right if there is a free-standing object (window, torch, sign) directly behind the place I want to put this beam. The beam doesn't snap, it just slides around like snapping is disabled until I am not pointing at the offending object behind the intended area. Please note that the object is usually about 6 blocks away from the area I want to place the beam.
This is on the Mac version, if other players are having this problem, please comment!