Example of the issue in Home Assistant, where the sensor was glitchy over the LAN, and the drop out is me flashing firmware 1.2.1, then it resuming proper operation. It looked exactly the same when bypassing the router earlier.

  @Joseph-TP 

Same config as you described.

Internet > Modem(Bridge) > Router ( NAT, DHCP, etc) > Servers and clients

Connection type is Dynamic IP mode.

And yes, 100% of the problems I was having cleared up when rolling back to 1.2.1

Oh and I mentioned a problem with the tether app. That was just my fault. My phone had tailscale running, so ignore that part.

  @Joseph-TP

When one of the first problems I noticed right after installing 1.2.3 was that I couldnt update an app on TrueNAS, and I worked with an AI to track down the problem, and this might point to what the problem might be. 

truenas_admin@truenas[~]$ for i in {1..10}; do dig +short ghcr.io; done
140.82.113.33
;; communications error to 1.1.1.1#53: timed out
;; communications error to 1.1.1.1#53: timed out
140.82.113.34
;; communications error to 1.1.1.1#53: timed out
140.82.112.33
;; communications error to 1.1.1.1#53: timed out
;; communications error to 1.1.1.1#53: timed out
;; communications error to 1.1.1.1#53: timed out
140.82.113.33
140.82.113.33
140.82.113.33
140.82.112.33
;; communications error to 1.1.1.1#53: timed out
140.82.114.33
140.82.113.33
140.82.112.34

This was not a problem with ghcr.io, and it also had a problem when forcing to 8.8.8.8 as well. And the problem was continuous the entire time with v1.2.3. As soon as I updated to 1.2.1 I am now getting zero of these errors.

Also the TrueNAS server is the only device on my network where I was using the custom 1.1.1.1 and 8.8.8.8 dns servers. The rest were using the ISPs DHCP assigned DNS servers. And as far as I know, it was only this server that was having these problems. And any device connecting to that server THROUGH the router had issues with it. If you were connected to the server outside of the router, like on a separate switch I have, I did not have any issues.