@PANGEN 

Hello,

Did you refer to this instruction to set up the WDS function?

https://www.tp-link.com/en/support/faq/327/

Note: When you set up the WDS function, please make sure you type in the correct password of your first wifi.

If so, please connect your computer to the TD-W8961N directly via Ethernet cable. Then check the IP address and default gateway of it.

Here is a FAQ you can refer to find the IP address: https://www.tp-link.com/en/support/faq/838/

1. If the IP address is 169.254.x.x, please check if you type in the correct password of your home wifi.

Did your router has any advanced settings, like MAC filtering and so on?

2. If the IP address is not 169.254.x.x, please reboot both your home router and TD-W8961N.

Please move the TD-W8961N closer to the main router.

You can try different devices to check the Internet connection.

If it still not working, please tell me the model number of your main router.

May it help nad have a nice day!