This is gtk-nocsd bug. Gtk-nocsd is not compatible with new HdyWindow. The debian version is unmaintained as of now.
The new code is https://github.com/ZaWertun/gtk3-nocsd.
Perhaps one can try with that library.
Note: If you install gnome-session you will need this patch from https://bugs.launchpad.net/ubuntu/+source/gtk3-nocsd/+bug/1745206
This is gtk-nocsd bug. Gtk-nocsd is not compatible with new HdyWindow. The debian version is unmaintained as of now.
The new code is https:/ /github. com/ZaWertun/ gtk3-nocsd.
Perhaps one can try with that library.
Note: If you install gnome-session you will need this patch from https:/ /bugs.launchpad .net/ubuntu/ +source/ gtk3-nocsd/ +bug/1745206