Window size changes after a reboot on Pi 5

[jimseng]

Hello
I can't find a way of getting openCPN to launch on boot to the last size I had it or maximized. -fullscreen works but then the menu panel at the top is covered and I have to toggle full screen and try and click the maximize button which is hard on a small touch screen. I have looked and can't see a way of doing it. It might be the OS doing it with the .desktop file in .config/autostart in which I have the command: Exec=flatpak run org.opencpn.OpenCPN and so I may need to look at tricks with xdtool but I wondered if any one could enlighten me.
Thanks