Dear Allie Flanagan,
Greetings! Thank you for posting in Microsoft Community.
Per your description, I understand you need help on syncing files from SharePoint folder from Mac Finder to SharePoint Online.
I'd like to help you, please let us cooperate, we can work together to narrow down and resolve the situation.
Firstly, you can follow steps below to set up syncing SharePoint files with OneDrive application on your Mac:
- In your browser, on your SharePoint site, navigate to the library of files you want to sync with.
- Select Sync in the toolbar. **Note:**If your browser asks for permission to use OneDrive, confirm that it's OK.
- Sign in to OneDrive to start syncing your files and finish OneDrive setup.
For more details, please check this support article Sync SharePoint files and folders - Microsoft Support
If you already followed those steps but you still meet sync issues, then you may try resetting your OneDrive application. Please refer to detailed steps in this support article Reset OneDrive - Microsoft Support
However, if you still cannot sync SharePoint files from Finder to SharePoint Online, I understand how frustrating this situation can be and sincerely apologize for the inconvenience caused.
Let me help you further. I would appreciate if you could share following information:
1.May I know if there is any error message when files are not syncing to SharePoint Online? Could you share some screenshots about the issue?
2.What is the version of your OneDrive app and macOS?
Thanks for your time and cooperation! I hope you have a nice day, stay safe and healthy always.
Sincerely,
Tina | Microsoft Community Moderator