I just encountered this same issue using Offset with a seamless .ai file, but only if that layer had “continuously rasterize” selected (which mine did because it was scaled up 800%.) My workaround was to pre-comp the illustrator layer, scale it up 800% inside the pre-comp, and then use that pre-comped layer at 100% in the main comp without “continuously rasterize” checked. No visible seam with Offset now.
Yes, output to 1080p30 (29.97) is what we are doing. We know this is not the optimal method, but considering the time issue, it’s good to know the tape we are delivering will be acceptable.
Thanks for the advice. I just discovered the problem was not with the computer at all, but with my SATA. I just used the computer without the SATA on and it worked fine. I suppose I should have tried that first. Thanks anyhow!