Lower layers showing at edge of composition

Hi,

I’m asking everywhere I can. I’m running up against a deadline and am at my wit’s end.

I’ve got a composition in AE with multiple layers. The contents of one layer are on top of another, in order to hide the lower layer’s contents before they appear on screen. The contents of that lower layer originate from outside the composition frame, and move down into the center of the composition.

Some users see what presents as a “line” where the lower layer’s objects are peeking out from behind the topmost layer (if the object originates from the top of the frame, the line is at the top). I have sent this file to multiple people who are viewing it on mainly the same, latest build of Chrome, but on different types of computers with different pixel densities and monitor sizes. On my 13" Macbook Pro M1 and the 2015 iPad Pro 12.9 that I’m using as a second monitor via SideCar, I see no problems with the animation. Others using 15" Windows laptops and 16" Macbook Pros with or without external monitors do see problems with the animation.

I cannot reliably test this on my own, but I also cannot fix it.

Things I’ve tried to fix the problem: extend the shape layer that is supposed to hide everything to well-past the edges of the comp, turn off continuous rasterization for all precomps and objects, turn off continuous rasterization for only precomps, add extra shapes in an effort to cover up that edge, move all objects into a single comp with no precomps. None of this works, and the monitors/computers that show the defect continue to show the defect.

Here’s the animation with all layers in one composition: https://lottiefiles.com/share/axuyxklm
Here’s the animation as it was originally build, with precomps: https://lottiefiles.com/share/sh9nvhi2
(pay no attention to the way the shapes do/don’t move around–the first link was for testing purposes)