[stiwi]

Have you tried deleting old NFS routes and try setting them up again? Look for NFS manager, it was just upgraded to 4.0 and it doesn't mention about NFS being an issue on El Capitan 10.11:
http://www.bresink.com/osx/143439/history.html

Maybe the way it needs to be setup changed a little bit but NFS Manager is point and click, it is also free. Can you give it a shot? I was about to upgrade to 10.11 but your post about broken NFS is holding me back.