i did create couple of cifs shares and given to MAC OS.
on and off, we are seeing a strange behavior form MAC side.
some times, the shares drop from the server and users are restarting their systems to connect it back
Some folders users placed are "greyed out" and have no contents.
seeing some folders disappearing, which showed back up after ejecting and reconnecting.
Just see if the solution mentioned in https://community.spiceworks.com/topic/2131095-mac-os-mounting-netapp-smb-cifs-share-hidden-grayed-out works for you.
this did not work out for us,