I've been trying to troubleshoot this as well. I followed the Brian Moses EconoNAS build pretty closely and used an existing case and power supply but with new parts inside:
- PSU: Corsair CX 500W
- ASUS Prime B450-A/CSM
- CPU: Ryzen 5 1600 AF
- RAM: 16 GB PC4 21300
- Boot Disk: paired SanDisk UltraFit 32GB
- HDD (RAIDz2) 6x Seagate IronWolf 4TB NAS
At first I thought it might have been the Plex server I was trying to run, so I cleared that. Still had problems. Also thought it might have been the upgrade I did (I didn't originally start with 11.3-U3.2 but had a slightly earlier release that I upgraded to that) so I did a clean install of the newer OS, still getting that timeout message from time to time. So then I started digging into new kernel modules for the Realtek ethernet interface on the board (I know I know...) but didn't feel like I had the expertise to build a custom kernel. And then I thought it might have been an issue with the Ryzen and compatibility with the OS.
So it is nice to hear that someone is getting this bug with server hardware, an intel chip, and a non-realtek NIC.
I was trying to give FreeNAS a shot after reading Brian's blog a few times over the years and thinking of my own NAS. I don't have any fancy network stuff like link aggregation or VPN or anything like that, I was just trying to set this up for internal home use. But I'm at the point of wondering whether something like Open Media Vault might not meet my desires and be less buggy for me?
I'm hoping to find out how you resolved this issue!