Major issues with nfsv4

[J David]

Ah, oops.  The "12.2 servers" referred to at the top of the message
are the NFS *clients* in this scenario.  They are application servers,
not NFS servers.  Sorry for the confusing overloaded usage of "server"
there!

Everything in the message (dmesg, tcpdump, nfsstat, etc.) is from the
perspective of a FreeBSD 12.2 NFS client, which is where the problems
are occurring.

Our Linux servers (machines? instances? hosts? nodes?) that are NFS
clients have been running NFSv4 against the same servers for many
years without incident.

Thanks!