Try to set the DNS address on the router manually to 8.8.8.8

Can you describe your problem more detailed?

You can try to disable UPNP. Also, may you post the log of your router?

I recommend you to contact to the technical support team. You confirm whether there has a beta firmware fixing this problem with them.

What's the hardware version of your 8960? You can try to modify the MTU size on your PC and have a test. If the modify have solve your problem, this should be a MTU size problem of this device. I...

TD-W9970 V1 should also support G.Vector and G.INP.