Upgrade to Apple TV 4K - now no wifi on Macbook pro?

Hi there,

I recently upgraded from Apple TV 2nd generation to Apple TV 4k. All I did was unplug the ethernet jack from the old apple tv and inserted it in the new Apple TV. However, my MacBook pro and MacBook air are no longer connecting to wifi. The wifi is fine, connecting to my mobile and pc laptop - just wont connect on macbooks - it says the laptop is "offline"? Anyone have the tv upgrade impact computer wifi?