The problem with unknown connections to app.

I have a c # app server on my VM on Azure. I send TCP requests on ports 4567 (which I already created the endpoint), on my server app I have a message each time a client connects to the VM: "Client connecting from IP: xxx.xxx.xxx.xxx". I got that message and it displays that an "app" or "machine" is trying to connect to my с# server app, the IP the message shows looks to be "internal address" due it looks like the IP is assigned to my VM. Previously, this was not, it started a couple of weeks ago.
How to get rid of this connections?
Regards.