What is this blank screen in avast suddenly popping up?

Hi, I am having the latest version of avast.
On each log in , after some minutes, i got a blank small screen popup from avast in the centre of the monitor without any alert? What is this pop up?

Hi, no reply for days. What has happened to moderaors and experts

You need to allow AvastUI.exe in your firewall.

Why does the UI need internet access?

That’s something for the devs to answer.