QT6's app's title bar double-clicking doesn't work on Gnome Wayland

First, QT6's apps' title bar is does not look like GTK or Xwayland apps' title bar (i.e., it's thinner and the 3 buttons are too small and crammed).

And double-clicking on the title bar does not work. It is supposed to maximise the window, but it only briefly shows the drag mouse cursor. Please see the attached screen recording below.