For anyone that's interested, OP didn't have a connection between his switch and the ISP's modem. Ethernet over powerline the probable (?) culprit. There were multiple hardware quirks that compounded the diagnosis. Two boxes, one with FreeNAS, then TrueNAS, supposedly wired; one Win11 Beta wireless and functioning box as a connection to ISP, both boxes on a KVM, sharing one monitor, mouse and keyboard.