UPDATE: due to the time-sensitive nature of correcting this issue (and on Christmas Eve, nonetheless), I opted to take a more extreme corrective measure. After backing up all of my data, I did a full restoration to default factory settings on my Mac mini. Once completed and my MacOS was updated to Monterey, I reloaded all of my saved data and reinstalled Xcode. By all apparent indications, this has resolved the issue, whatever the cause. I should add that the "previous software issues" I was having with Xcode was that while attempted to stop running processes and close the software, Xcode simply gave the endless "spinning rainbow wheel" and wouldn't close. I'm relatively new to Mac, so perhaps this was user error. After an inordinate amount of time, I opted to force close Xcode and restart my Mac. Once restarted, the issue with Xcode failing to build the preview cropped up. Thank you for taking the time to respond to my issue, and happy holidays to you and your family! God bless you.

I believe I have the Diagnostics Report you refer to above (my folder is named: "previews-diagnostics-20211224-212138"), but unsure how to send you the files that you need. When I clicked on "Generate Report" and "OK", the window simply closes, presumably having sent Apple the issue specifics? Forgive my ignorance. Please advise, and thank you for your assistance.