Storyboard Pro Exports Harmony Files Slightly Out of Sync

I’ve had this issue for quite a while now with Storyboard Pro, I’ll be creating an animatic for an animated music video, when its finished I’ll export the animatic as separate Harmony files, and then animate the scenes in Harmony using those files.

When they’re animated and composited I’ll then start compiling them together in Premiere using the original song audio file and the finished animated scenes rendered to MP4s. When I’m editing them together I notice that the further I get into the Music Video the more out of sync from the original animatic it gets and my initial cuts don’t match perfectly.

I could move around and adjust the scenes to fit, but I’ve already animated and done the lip sync to these slightly out of sync files (as when I’m looking at say scene 64 which is 180 frames you can’t tell that its a few frames out of sync to the original Storyboard Pro file).

This issues normally means I have to do a mix of slightly slowing or speeding up the scenes to get them the right length to match the edit, and the ones with lip sync I have to go back into the Harmony file and retime and adjust them and then export them again.

Has anyone else had this issue and know how to prevent it?

Thanks for your help!