Headclient Freezes processing when focus is lost?

[Michael0100]

As the subject says.

For some reason, clients cannot connect when the client loses focus.

The server is a 10900K @5.3 All core, 32GB, GT-1030 on Windows 10. It's a server dedicated to just hosting games and only running Teamviewer & Factorio.
It seems that when I click off of the game, it will lock up or if I end the Teamviewer session it brings up a diag box, which again makes it lose focus. I can access it with the hardware mouse, so I can mitigate the issue, but it's incredibly frustrating.

Is this a known issue, have I missed something?

[Rseding91]

The only thing I can think of is: in windows 10 at least when you click on a console window it starts to select text and that blocks anything from writing to the console. If that's happening it would act like it's frozen from the games perspective.