Fact check

Determine the folder that is missing in the users network share, and then map the same network share to your local PC. If the folder is also missing on your local PC, the folder that the user is looking for in the network share no longer exists in the share.

Mapped to subdirectory

The user may have the network share mapped to a subdirectory. For example, instead of mapping \\example\share, the user may have mapped \\example\share\sub. You can disconnect the mapped network drive and then map the network drive again, this time mapping it with no subdirectories (\\example\share).

Registry

The Registry may be configured to automatically reconnect the network drive at login. Follow the instructions in the article on how to stop a network drive from reconnection at login.