I run an Ubuntu 24.04 desktop with an NVIDIA card, and "flatpak run app.vger.voyager" gives me a white window and the error "Failed to create GBM buffer of size 2400x1600: Invalid argument"

If you run into the same problem, what worked for me is:
flatpak run --env=WEBKIT_DISABLE_DMABUF_RENDERER=1 app.vger.voyager

If you have this same problem and the above command works, you can make the fix permanently with:
flatpak override --user --env=WEBKIT_DISABLE_DMABUF_RENDERER=1 app.vger.voyager

Then "flatpak run app.vger.voyager" will work.