A square black border around start button

[musician84]

A square black border is appearing around the Windows 11 start button upon windows start-up. It goes after a while.. I'm not writing this as an issue. But wish to know why this occurs and make Open Shell an excellent option for windows start menu. please find attached image

[ge0rdi]

I have no clue why is that happening.
Though I don't think it is related to Open-Shell as we don't do any modifications of taskbar on Win11 (as that uses completely new XAML framework).

I assume you don't use custom start button image, right?

[musician84]

I am using original start button only.