I was going to say "it's the WAN port", but your switching table says otherwise.
Have not encountered this. I would suspect either hardware fault or firmware fault.
1. Have you actually applied the settings you screenshot?
2. Did the issue exist with the factory (non-OpenWRT) firmware?
3. Do you even get a link light to come on when you plug another device in? Make sure it's a full desktop computer, some portable devices with RJ45's (including printers &
some usb-ethernet devices) are lazy with their link detect & don't send pulses out.
4. Run wireshark on a computer plugged into that port and reboot the router. See if the port gets enabled by the bootloader for a few seconds at the start of boot. If so then it's probably an OpenWRT issue.
Obligatory: it would be better to ask on the LEDE/Openwrt forums