Hmm...
This is very likely caused by the kernel disconnecting the mount, or maybe OSXFUSE disconnecting the mount. Now why it has disconnected the mount is a different question!
Here is another thread with a similar issue: Sonarr / Radarr Hangs when using cache temp upload path - #26 by jrock which is when I introduces --daemon-timout
One thing that occurs to me is that you might need a new OSXFUSE for daemon timeout to work.