basicly it looks good so far, only the toggling state before you read out the sfp is strange…but this looks like manual switch from sfp2 (lan sfp cage) to sfp1 (wan sfp cage = eth1)
so what exactly does not work? the 2500 Mbit/s SFPs (the TP-Link you have and the OEM i have) have a bit problems recognizing the link and link speed we are trying to fix. so for now try the autoneg workaround to get link working
Using the commands you provided is still not good, I can’t get an IP address when my problematic network cable is connected. Looking forward to your fix.
root@OpenWrt:~# ip l show eth1
3: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq master br-lan state DOWN mode DEFAULT group default qlen 1000
link/ether 9a:31:8a:46:a5:e7 brd ff:ff:ff:ff:ff:ff
root@OpenWrt:~# ip a s eth1
3: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq master br-lan state DOWN group default qlen 1000
link/ether 9a:31:8a:46:a5:e7 brd ff:ff:ff:ff:ff:ff