This seems like a similar issue to something I've run into running 2019.10 (and.6) and Mac OS Seirra 10.12.6.
Here's a link to a thread from earlier this year. I hadn't experienced the error most of the year until it happened again to me today. The main symptom is a corrupt session file and several corrupted back ups. The corruption is evident by the size of the session file back up. After the error, it's much smaller than before. All of the back ups have missing audio and/or clips addressing the wrong audio, but there is no way to re-link anything.
http://duc.avid.com/showthread.php?t=405902