New router won't connect through ethernet WANport

I have a recently purchased gl-sft1200 travel router. My ethernet has been tested and it works on my old router.
When plugged into the WAN port, the admin screen shows it is connected to the ethernet and shows all the correct protocols.

Then it crashes and says " No cable detected in the wan port"
Then it reconnects and does it again over and over.
I have used several brand new ethernet cables with same result.
I would appreciate if someone could help with this matter
Thank you

Please try this command in the SSH:

#Check the WAN interface name
ifconfig
#If the WAN is eth1, and fixed to 100Mbps
​ethtool -s eth1 speed 100 duplex full

Can you please give me instructions on where and how to change those settings?

Connect by SSH to your router using the "command" root@router-ip
How to connect by SSH depends on your operating system, see How to Use SSH to Connect to a Remote Server in Linux or Windows

I followed the instructions and installed bitwise for the ssh settings.
Still no internet connection.
Should my router settings be static or DHCP?

Just confirm in my SFT1200, the ethtool command does not support for the WAN interface.

May I know is the primary device (WAN) Startlink?

Please export the syslog and PM me.