Why is Syncthing trying to talk to various IP addresses?

I have installed Syncthing but not really tried using it. However, Malwarebytes keeps blocking Syncthing accessing various IP addresses on the Internet.

I have disabled Global Discovery and checking for updates. So why is it trying to talk to random IP addresses?

I only want to use it on my internal network.

What do I need to do to stop it doing this and why is it doing it?

You need to disable Relaying too.