Attaching NFS Virtual Media fails after iDRAC 6->7 firmware upgrade

I have been using the following command to attach an ISO from an NFS share to virtual media:

racadm remoteimage -c -l nfs.domain.com:/share/image.iso

I patched the firmware on 2/7 Dell Poweredge R6525/R7525 servers from iDRAC 6.10.80.00 to 7.20.10.50.

Now the systems with the newer firmware are unable to mount the ISO via NFS with the following message:

RAC0720: Unable to locate the ISO or IMG image file or folder in the network share location because the file or folder path or the user credentials entered are incorrect.

Enter the correct file or folder path and credentials, and then retry the operation.

I should also note that this worked okay older generation hardware as well (all the way back to R620s running 2.65.65.65) I am suspecting that firmware version 7 has changed something with it's NFS requirements that are perhaps no longer compatible with my upstream NFS server (which I do not administer). 

My next step is to start looking through all the change logs for iDRAC firmware, but if someone knows the answer to this issue it would be helpful. 

For reference when I have this share mounted on a linux machine here are the options:

rw,relatime,vers=3,rsize=131072,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=X.X.X.X,mountvers=3,mountport=300,mountproto=udp,local_lock=none,addr=X.X.X.X

I am suspecting that maybe NFSv3 might have been dropped? If so, that's kinda ... nuts. And it doesn't bode well for dealing with systems from mixed generations of Dell hardware.