I have sound from a video but no sound from mono wav files on 5.1 multitrack

I got an AAF of a short film and used AATranslater to create an SESX file from it that I opened in Audition.

AATranslater converted the aiff files into .wav, too. I've done this before with no problem.

The mono .wav files populated a stereo multitrack from the AAF/SESX conversion and I copied them to a 5.1 SESX session I created to mix in.

I then added a video with a stereo audio track attached, which plays nicely when the spacebar is pressed on the multitrack.

The mono .wav files do not show any meter or make any sound when the timeline is playing, but I can hear each file perfectly in the waveform editor.

I checked the output routing and they are all set to Master.

I know my surround is working because I can pan the audio from the video to all of my speakers.

This is very weird and frustrating.

What else can I do or check?

Thanks 😕😕

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