Alembic sync issue with Media P

Hi,

I bring in an alembic geometry as geometry Cache.

I also bring in an mp4 video that is to play as a texture on the geometry.

It works okay but they are out of sync? It feels like the geometry is playing at a slightly different frame rate than the mp4.

Both are set to 30 fps.

I have set the project to have a fixed 30 fps rate.

Any ideas??

Thanks all!