Bug: Movie audio track being duplicated/coming out of multiple audio interfaces/not visible in mixer

Ran into this crazy bug today and thought I'd share my experience in case anyone else comes across it.

I've been scoring a trailer that has an SFX track embedded into the video, and have been importing new iterations regularly to update the score. Normally when importing the new movie file I would check "extract audio track" but today I imported the audio track manually, so I didn't choose this option.

There's this big slam sound by itself at the end, which I had sent by itself to the video editor, so it was part of the SFX track, I have it muted in my score. I started noticing something weird when that slam hit, it sounded phasey and weird, and despite having everything muted I was still hearing it.

Was driving me absolutely mad because I couldnt figure out where the duplicate was coming from until I changed Logic's audio output to my MacBook speakers, and the SFX track was still coming through my UAD interface.

Deleting the movie and re-importing it with "extract audio track" fixed the issue (was the same audio as the one I manually imported), but this was an insane bug to experience today.