Captivate 2019 Publish to MP4 not working?

Hello. We have a number of .cptx files from Captivate 2019 published to Adobe Connect and I also need to publish them to mp4 now. I followed the steps on the support site/user guide, but all of my published mp4s save down as 0 bytes and can't be played. I've tested the custom presets and Captivate claims they work.

Any thoughts on how to fix this? Am I just not giving them enough time to process? The first video I "published" about 25 minutes ago and it still says 0 bytes.