One of the things I find annoying about Ubuntu Desktop defaults is that when I open a new application it opens in the upper left corner. I then drag it to the center screen and start working. It’s amazing how a small inconvenience can grind on you over time. When I’ve search the net for changing this behavior the usual suggestions are “install gnome-tweaks”. This seems ham-handed. I think continue searching and eventually find the command below. So I am making a note of the command here in my blog so I can find it latter.
gsettings set org.gnome.mutter center-new-window true