Hello everyone!
Yes, the little drawing next to your documents folder in OneDrive indicates that the folder is shared. To unshare the folder, follow these steps:
Open the OneDrive folder on your computer.
Right-click the folder you want to unshare.
Select "Manage Access".
In the "Manage access" window, click the "Stop sharing" button.
A confirmation window will appear. Click the "Stop Sharing" button again to confirm.