Motion title isn't rendered in output

Basically, I've just made a new motion title for a video project that uses a Replicator that I've keyframed for objects to appear and disappear. In FCP and Motion all the objects show up OK, but when I export the video through Compressor it doesn't render the replicator at all.

I've tried making a duplicate, changing the source image for the replicator from a PNG to a JPG, deleting all of Final Cut's render files, and converting it from a Title to a Generator, and all of them do the same thing. Deleting Final Cut's render files and stopping Background Render also stops it from showing up.

I made sure that "Preserve Opacity" is disabled, and I've gone as far as removing the drop zone behind the title as well just to make sure. The only thing I can think is that because I made the Motion project at 4K 59.94 and the timeline is 1080p 29.97 it doesn't like it but I've been able to use my other Motion projects like that with no problem. Is there something obvious I'm missing?

Quick update from giving some stuff a try - I've noticed sometimes when I'm opening the motion project the Replicator stops showing in Motion - I have the Replicator's "Points" parameter keyframed and usually I have to delete and undelete the keyframes for it to behave itself again. I've switched it to a ramp behaviour to see if that helps