Stereoscopic video material works on Vive but tiles incorrectly (in one eye) on Go

I'm working on a stereoscopic 360 video project to run on Oculus Go, so my videos have a stacked, left eye on top of right eye layout. I think it may be a bug with the Go because my materials play video correctly in PIE and on my Vive headset. But on the Go, the eye receiving the texture sample's UVs that I've circled in red, only displays 1 sliver of pixels, stretched across the sphere- or any mesh I apply it to. Does anyone have experience with the Go OR another way of working with the new custom node we've needed since 4.19 to make this stereo stuff work? I already wasted a week trouble shooting a tutorial I followed perfectly, only to discover it became obsolete after UE 4.18 because they changed UEs render methods. We want to buy 9 more Gos for a tradeshow in a couple weeks that this content will play on so I hope it's an easy fix. I'm using 4.21.