The gnome version of debian 10.x, and only that one, uses wayland instead of xorg. So, other than using a gpu driver that is capable of working perfectly under wayland, e.g. NOT the nvidia closed source driver, make sure that any app you are going to use works with wayland as well. That includes opera.
Else, switch to session to "gnome with xorg" and use that to test how opera works there.
Opera for Linux