Copy/paste between Carlson Survey and C3D

I'm in a situation where I'm working with a client, and I'm using C3D.?ÿ I'm doing some work in Carlson, since I'm used to it and find it easier.

I can copy from C3D and paste into Carlson at 0,0 successfully.?ÿ But when I try to do it the other way around, it doesn't work.?ÿ I then need to WBlock out what I want to bring into C3D, and that works fine - so I can achieve my end goal.

I'm just curious why this procedure works fine going one direction, but not in the reverse.