Blue line at the top of a Brave window

In windowed mode, a blue line is visible at the top of the window.
With an open instance of Brave, just drag it down to enter windowed mode. A blue line should be visible along the very top of the window.

Brave 1.3.115

I don’t have such a line (Win 8.1, Brave 115). Why don’t you have a frame around the window? Do you use any utility to change the GUI?