This is especially true if the network/Samba file share is not present or currently inaccessible. If you have a network folder or FTP links (e.g., project folders located on another computer on the office network, accessed via a mapped network drive, or FTP links pinned to the Quick access list.) pinned to the Quick access, File Explorer may fail to refresh the folder automatically.
RELATED: How to Restart Explorer Cleanly in Windows 10 Unpin Network share/folders or Reset Quick access