Sue,
Not sure but will give it a try.
Sounds like a writes issue. Many times if the user does not have full rights to their computer there can be issues with files and the ability to change the files or copy.
or... do a right click on the DST file and see if the file is Read-Only. That might cause the issue.
one more question. Are you running 2025 AutoCAD? We use OneDrive with 2025 and noticed with the Collaboration that is inside AutoCAD now and having files on OneDrive.. it makes multiple copies with -01, -02, etc. I will be turning off Collaboration this week. This also allows others to open your drawing and it does not let you know it is open. They don't get a notification as well and work on it. Save the file and it does -01. If you don't notice that.. the real drawing has not been touched but a 2nd copy now has updates. Not a good thing in my opion.
I hope one of these ideas helps.
Thanks, JRR.