Hi Mark,
Thanks for the reply. Further testing reveals the issue is not caused by any particular data file. I was able to repeat the behavior with an untitled empty file. Due to project deadlines, I have downgraded to 2019, which is stable on this Windows PC.
Do you have access to the BugSplat report I sent from the Windows PC? Hopefully, there will be useful data for your diagnosis.
On the Mac, I continually get BugSpat crashes. I have submitted >20 reports to Apple and SU. This link provides more information. @colin looked at some of the reports.