Thank you for confirming. Since you previously mentioned that OneDrive synchronization failed several times due to insufficient storage, the fact that you currently have 5 GB used out of 50 GB does not rule out earlier synchronization problems. Some files may never have been successfully uploaded to OneDrive, which means you should focus on locating their original copies on your computer.
Please open File Explorer, press Windows + R, and check each of the following locations separately:
%UserProfile%\OneDrive\Desktop
%UserProfile%\Downloads
Also, open This PC and search for the name or extension of one of the missing files (for example, *.docx or *.pdf). Please avoid resetting OneDrive, unlinking your account, or making significant changes to the files while we investigate.
Could you let me know whether you find any of the missing files in these locations? Also, when you click the OneDrive cloud icon in the taskbar, does it display "Your files are synced," or does it show any synchronization errors?