If you been able to replace this issue on SW2016, please contact your reseller to have them look into this issue, and if necessary, file a bug report (or resolve the issue if they have a method).
I tried to replicated the issue and was successful, but only after I used the Move Entity function; I could not just drag the point away after creating it. After using Move Entity I was able to drag a spline to line intersection point anywhere, but not a line to line. Both kept their Intersection relation. Interesting.
I created the above points by selecting both lines and creating a point.
I tried with the Find Intersection command in dimensions (Dimension>RMB on line>Find Intersection) and that point was immediately drag-able.