Why my splines are moving all together when only one is selected? I'm very new to blender so sorry if I say stupid things.

I am trying to put a series of splines along a circumference (at different distances so I can't use duplication... I suppose)

For easiness I set the origin of the splines at the center of the circumference with CtrlAltShiftC "Origin to 3D Cursor" but when I try to "move" one single spline along the circumference (rotating with RZ) even the other splines are moving with the selected one.

Edit: I've switched off proportional editing but still doesn't work.
I found a solution by myself. The problem was the "Origin to 3D Cursor".

All my splines origin were on the 3D cursor so it seems Blender tought all of them were the same object...is that possible?

Anyway I solved switching to "Origin to Center of Mass" with CtrlShiftAltC. That solved my problem.