Microsoft 檔案裝載和同步處理服務。
Dear Josh,
Thank you for the updated information.
Based on your description, when the user tries to sync OneDrive to the local, an error about the Delete file will pop up. However, the user didn't delete files both local and online.
You could try to unlink OneDrive and run OneDrive setup again to see the result via Help & Settings > Settings > On the Account tab, click Unlink this PC and then Unlink account > Follow the steps in the Welcome to OneDrive wizard to set up OneDrive again.
If the problem persists, you can try to reset OneDrive. Resetting OneDrive can reset all OneDrive settings. After resetting successfully, you can try to setup it up again to see the result.
Sincerely,
Jazlyn | Microsoft Community Moderator