I noticed this in dooble_main.cc,
#ifdef Q_OS_WINDOWS
QCoreApplication::setAttribute(Qt::AA_UseSoftwareOpenGL, true);
#endif
Tried adding Q_OS_OS2 to the ifdef, webgl crashed the browser when used. So read up on it,
https://doc.qt.io/qt-6/windows-graphics.html.
It is to load a non standard 3D driver including a software solution, they suggest Mesa llvmpipe which would need lvm. There are other software OpenGL drivers around such as TinyGL or PortableGL. Mentore has built TinyGL and I've built PortableGL previously IIRC.
The problem to overcome is that Cloudflare has become the gatekeeper of much of the internet with it's "Are you human" checks. These depend on WebGL to display, so we just get a spinning circle. Even a really slow 3D renderer would be better then nothing for these cases. And actually, given a small window, software OpenGL often doesn't perform too bad.