Alpha Video: Black line when prepping in After effects

Studio
#1

Hey there! I followed the alpha video tutorial, but I’m using after effects instead of Premiere Pro, and getting a black outline on the mask version of my animation. Everything works in the experience as it should (aside from some minor scaling issues) but I need help getting rid of the black outline.

This is what it looks like (on a white background, but its on a black background when I export the video)
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and here’s what it looks like in my zap:
image

any suggestions for how to fix this?

Edit to add: All of my assets in the animation are vector shapes directly imported from the same adobe illustrator file, so it’s not that the assets originally have the outline

#2

update! I was able to get rid of the black outline in after affects by turning off the RGB channels, which leaves a black shape from the alpha channel, and then adding a white color fill over it.
image

however, studios still shows the black outline in my experience, so im not quite sure what’s up now…hmm…
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