Sharepoint/One Drive won't sync files or folder into Cloud

Folder maybe corrupted , or you may have conflicts .

Folder automatically duplicates in SharePoint - Microsoft Community  

1. Ensure your  One Drive App is up to date, signed in and sync is completed 
   
   
2. To resolve, Create a new Folder and copy the files to the new Folder and wait for them to Upload to One Drive. 
3. Once confirmed you can remove the old folder that wont sync into one drive.
4. Now you can rename the new folder to want you desire 

Below is example of problem with Sharepoint