Flatpak installed app displays a blank window and crashes after a while

It looks like you're using the old Flatpak from Flathub (0.0.8). Fluxer now provides its own official Flatpak, which you can install from the download page: https://fluxer.app/download#desktop The Flatpak install command listed there is: flatpak install https://pkgs.fluxer.com/flatpak/fluxer.flatpakref Might be worth trying the current official Flatpak first and checking if the issue still occurs there.

Flathub build is mostly prepared https://github.com/flathub/app.fluxer.Fluxer/pull/14 but blocked due to flathub requirements https://github.com/fluxerapp/fluxer/pull/2872 will likely fix the issue once merged