Hi David,
I think GH v0.6.0059 have a bug with the Amplitude component. It seems that it always add an unnecessary vector in the outputs. I noticed that the bug vector equals the v-input vector.See attached picture:
Are you sure the input geometry for the Move component consists of just one circle? Because of the wires I see on the picture, looks like There's more than one element. Only one vector and more than one geometry (for the output you get, looks like you have two circles)
If its not that I don't know... but I'm sure there's only one vector comming out from the Amplitude component (look the simple wire)