Apologies for the necropost, but thisThis issue just hit me on a Mac running Ventura 13.2 accessing a QNAP with NFS. Wound up with a stale NFS handle that would not go away despite reboots of both devices.
To confirm, just logging into the server using sshssh and doing exportfs -ra
exportfs -ra without anything else, no (no config changes, no playing with fsidfsid, no other actions, just exportfs -ra on the QNAP, and) made the problem wentgo away.