it has gotten a bit dirtier. However a leading cause also is interference from other objects interrupting the plane. The engine currently is having a great deal of trouble with multiple objects on the same or close snap-points, or being 'blinded' by intermittent objects.
One easily repeatable situation is crossing beams, where a diagonal one stretches through where a horizontal beam is being placed. Large X-members display the same behavior, it is quite tell-tale. Or multiple 45's getting attached to a vertical beam at the same point. I can hassle with one snap-point for an entire in-game day to get it to finally land. Sometimes its easier to destroy other stuff and then rebuild it. It certainly could use some finer tuning, along most of the other tools.