Multitrack mixdown in Audition CC 2019 suddenly takes FOREVER

I upgraded to 2019 earlier today, and now all of a sudden trying to export a multitrack mixdown brings Audition to it's knees. Here's my situation:

I use Audition to mix together music files in MP3 and AAC formats for a radio show, and I typically use a 2 hour multitrack file, with around 5 tracks plus master. Most of the time I'm just mixing two tracks together, occasionally throwing in a station ID or show intro or outro onto a third or fourth track, nothing too fancy effects-wise beyond Audition-specific fx (Studio Reverb, for example). There's crossfades and some envelope adjustments but really, nothing too difficult. Until today, multitrack mixdown exports to WAV or AIF format have taken, on average, about 5-8 minutes of real time to complete. After upgrading, the file I'm currently working on is currently at 45+ minutes and the time is actually INCREASING as I sit here. I've seen a few older questions with similar issues from previous versions of Audition but nothing that I've seen answers this problem. Any ideas?