I’m not sure if we’re hitting a dead end here. Might be the retries are just symptoms of a saturation of one of the component in the intranet including the NICs but the reported bandwidth should be high enough for any video stream.
I suggest to switch the NFS stack and use kernel NFS instead of the kodi’s NFS implementation.
@nicheplayer Have a look at Mounting network shares with autofs (alternative to fstab).
By that you mount your sources to a point in your local root file system but have to setup again the sources in the mediacenter accordingly (and remove the old one).
Another advantage would be that we could easily test the file transfer from the NFS server with Linux on-board sources and tools.