Can't render sabre correctly in AME

I am currently trying to render a facecam border I quickly made for a friend as a webm file through media encoder via after effects however everytime I try to render with an alpha layer the Sabre plugin doesn't render correctly and instead is just displaying as a large white box.. see screenshots below

This is what i'm getting

This is what I want...

I'm currently rendering as 1500x1500, 30fps, 30s length

quality is set to max on a VP9 with alpha enabled

Audio is disabled

please help, i'm running out of ideas here...