[Dave Faulkner]

Hi
I had the same issue and came up with this solution in AFX v17.1.1 on a mac.

In the motion tiler effect increase the ‘output height’ which makes the tiles go beyond the edge of your comp (even though you can’t see them). I increased the output height by 400+ for my project.

You can now animate the position of your whole comp to go the opposite way of the motion tiler phase movement e.g. if the motion tiler ‘phase’ is making every other column move downwards you just animate the whole comp’s position to go up on the Y axis.

You could increase the motion tiler ‘Output Width’ and then animate the whole comps position on X axis if you wanted to do similar but with horizontal rows.

I hope this helps. (Explaining stuff like this in words is tricky).
Cheers
Dave