I'm quite sure it's a Finder issue. Indeed, you can access your share using a terminal or another file manager. To use Finder, you can try the solution reported here and here.
It is a temporary fix, but it works as in any previous versions of OSX (i.e. it survives the sleep mode etc.). I recap the solution here for the sake of documentation.
Mount CISF/SMB in "Findable" way:
- Mount the share using Finder (e.g.cmd+K)
- Close the Finder window
- Turn off the network connection (eth/WiFi etc.)
- Open a Terminal:
- Run the command:
open /Volumes/$sharename
- Restart the connection
- Open again the share with Finder and it should work as expected.