I have been porting my software to Gtk4, and found that under X11 my
ApplicationWindows always start up in the upper left corner of the left most display.
It does work correctly under Wayland. This is on Fedora 34 system.
I find with
WM_NORMAL_HINTS(WM_SIZE_HINTS): program specified location: 0, 0 program specified minimum size: 46 by 46
I looked though the gtk sources and it seems
gdk_display_create_surface() has x, y arguments
that are passed wired at 0, 0 most places, which
could be setting up the hook in
gdk/x11/gdksurface-x11.c. I am not familar enough with X11 WM hints
to follow exactly what is going on.
Is this a bug I should report?