NEAR 3D compared to NEAR results

I am not getting the results i expect in near3d. I have 3d point data representing trees(1600 3d points) and 3d line for powerline(2 lines),
These are created from LiDAR data.
When i use NEAR (2d) I get correct results( 2d distances) .The same data using Near 3d is not correct
map1 = results near correct near fid in point data red near line fid=1 , green near fid=2

map2 The trees that are now green and red in map 1 are incorrect and calculating distances and z values to line fid=2.

Also the red and green trees that are same in both maps give correct results for NEAR_DIST AND NEAR_DIST3 AND Z VZLUES.

No trees are >50m from any line, but using near 3d have distances up to 280m (in both NEAR_DIST and NEAR_DIST3.
I leave the search radius empty in the near3d tool.

Could this be a bug in NEAR 3D or am i using the tool incorrectly.
Malcolm Pugh

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