"No Internet" pop up message appearing every time my MacBook wakes up

Hello,

Since having used the wifi at a friend's home, I am getting the below pop up every time my MacBook wakes up.

I can only clear the message by clicking OK.

It seems a little odd as I've never had this before and can't find a way to either hide it or disable it.

Any assistance with advice on what this might be and how to resolve this would be greatly appreciated.

Thank you.