When a network share is stalled, the easiest way to get out of it is a host reboot. Or you can try to lazy umount the share and remount it first, but no guarantee.

@TeddyAstie Thought...If you want access to a server with a B50, I think I could setup VPN access and put a host online with IPMI access for you to do whatever you want with. You will have an AMD Epyc 7302 with 64GB of ram some flash and HDD storage, and an Intel B50. PM me and we can work out the details of what you need to experiment with, and I can setup some remote access for you to get into the system. I will gladly work with you guys any which way I can to move this forward.