I found it can be rolled back if I go Preferences > Preferences > Schematic editor > Display options and select the Fallback graphics as Rendering engine, but these changes are there only until the next start of eeschema. How to make them permanent?
If I recall correctly, Ubuntu 21.04 defaults to wayland and classic xorg calls revert to software rendering via Xwayland
This is due to be addressed in the next beta series from nvidia (470… presently 465) as nvidia will provide hardware accelerated xorg calls as well as finally support GBM (not their EGLstreams…) as this will permit other wayland composite managers to work with nvidia since only GNOME and KDE support EGLstreams
yup, an NVidia card,
so … assuming you are using Wayland that probably explains the initial visual issue since wxWidgets only support EGL in the development branch and thus 3.0.x will use X11 calls and thus will go via Xwayland (exposing this issue).
Obviously if you are using xorg instead then this theory is out of the window. Hopefully the 470 series of drivers will bring EGL support and hardware accelerated XWayland and thus permitting using the Modern toolbox.
I am holding off switching to Wayland until the 470 series