File creation time in C#

You need to use Refresh:

FileSystemInfo.Refresh takes a snapshot of the file from the current file system. Refresh cannot correct the underlying file system even if the file system returns incorrect or outdated information. This can happen on platforms such as Windows 98.

Calls must be made to Refresh before attempting to get the attribute information, or the information will be outdated.

The key bits from MSDN indicate that it takes a snapshot and attribute information..will be outdated.

Try using FileInfo and Refresh method of it

fileInfo.Refresh();
var created = fileInfo.CreationTime;

this should work