I have 20 GL-MT300N-V2 routers. In 18 of the routers i have an issue where no cable is detected in the WAN port half the time. I have tested them on multiple networks with different cables and they all have the same issue. The only way to get it to work is to power cycle the device and hope it detects the cable that time. I have tried different firmware version and the issue persists. Is there any way to fix this?
Can you run swconfig dev switch0 port 0 show to see the return result?
root@GL-MT300N-V2:~# swconfig dev switch0 port 0 show
link: port:0 link:down
Most likely it is your cable, you can try to change the cable