I had same problem after latest OSMC update.
OSMC could discover my samba share (Apple Time Capsule), but could not see any of the files. My MacBook still worked the same with the share, so I guessed it was not an issue with the Apple TC.
So, I added a line in my /etc/fstab on OSMC which auto mounts
the samba share automatically on boot up.
Seems to be working fine - apart from the fact that now I have two of everything in my libraries 
Let me know if you want any details, or if you want me to try anything.
Thanks.
Best regards,
Niall.