You should have unmounted the NFS share before stopping the NFS service on the server, now you [most likely] have a dangling mount. If you try to `ls` the mount point, does it still show the contents, or is it blank, or does it hang?
I would first try unmounting the mount point. If that doesn't work, try to force the unmount (-f flag). If that doesn't work, try a forced lazy unmount (-fl). If that
doesn't work, you can try this: