Hi ScottAdleman,
Please follow the steps below to see if it helps:
- Search for a file which will be in the same folder as your document and will have a name the same as your file but with ~$ at the start: CMD + F
- Select them and move to trash. Make sure that all the users in your organization delete the ~$ files and open the file to see if you can edit it.
- The ~$ files are supposed to be deleted when Excel and/or the file is closed.
If Excel quits abnormally, the file may be left in place causing the lock for editing.
This problem often occurs when you shut down your Mac directly before you close Excel or the file.
So make sure to close all applications before you shut down.
In addition, here are the common troubleshooting steps for your reference: Excel file is locked for editing by another user.
If the suggestions above don’t work for you, to better understand your situation, please help confirm the information below:
- Does this issue happen with all files or a specific file on your Server?
- For the “never had the problem before but starting in 2018”, what changes do you make before 2018?
- Capture a screenshot of Office name and version to share with us according to this article: What version of Office am I using?
Best Regards,
Gloria