Audio cuts out completely, then video begins stuttering (OSX 10.13.3)

Hello all,

We've had an issue that has affected a couple of our edit rooms sporadically (spanning a couple Premiere updates), and we haven't yet been able to pin down a cause.  Right now it's happening on a sequence to the extent that we can't have a producer screen it.

While playing down a sequence (XDCAM HD 1080p30), the editor will hit a point in playback where the sound cuts out entirely (in this case, about 45 seconds in to the clip).  After this, if you let it continue to play, the video begins stuttering badly, along with occasional 'blips' of being able to hear the audio. 

We only edit short form, so none of our sequences are longer than ~13 minutes, but we've run into this on multiple machines, in various projects over the last year or so.

One thing we noticed in this case: at the point where the audio cuts out, the video switched to a clip that an AE had accidentally transcoded to 24 FPS (the editor never uses camera raw - the AEs sync and export the interviews as full-length clips due to the way that our media management software (eMAM) handles filenames.

We re-transcoded that interview, and edited it back in as the correct frame rate, and now it plays through that part reliably, but afterwards we hit the same problem, this time with nothing apparently unusual about the media it cuts out on, even happening at points where it had previously played without issue. Upon export, the problem is not present (though we did notice a frame that 'flickers' during transitions - that's a separate issue).

We're using Late 2013 MacPros with 64GB of RAM all running High Sierra, 10.13.3 with AJA cards for audio I/O and external video (we tried switching to line out to bypass the AJA and rule that out with no luck).  The media is playing off of an EditShare RAID6, and the project is imported & exported using eMAM.  Premiere Pro has been updated to the latest available version.  This problem doesn't happen on EVERY project, but it happens more often than not (one editor says it happens on every project, another says only sporadically).

Anyone have any ideas?

Thanks very much,

-Aaron