Question for Artist Mix/Control users... Cubase 7.5.1

I recently installed an Artist Mix/Control and so far so good. I do have one issue though…

When I am writing automated fader moves, occasionally the write does not get saved. The channel strip is in automation write mode, I can see the mix console fader moving in conjunction with the moves on the surface but when I play back the automation does not replay.

Has anyone else encountered this and if so is there a trick to this procedure?

Thanks