[JangoSteve]

I think the magnets on the track piece may be arranged NSN like this:

  NNNNNNNNNN
  SSSSSSSSSS  ==>
  NNNNNNNNNN

Which allows movement as indicated. In the part of the video where it's just locked stationary above a square magnet, it appears maybe the magnet as this arrangment:

  NNN      NS
  NSN  or  SN
  NNN

Which locks it entirely in-place, not allowing movement. And then in the part where it's spinning, I think maybe the magnet is S on the inside and N on the outside or something:

      NN
     NSSN
    NS  SN
     NSSN
      NN

Allowing it to spin. But this is speculation based on my limited understanding (but I noticed no one else was answering, so I thought I'd give a shot).