Synthaxx

Either something is wrong with your setup, or your hardware. Make sure that you’re running the right drivers and that you aren’t accidentally running on your onboard graphics instead of your dedicated GPU.
Check the general Linux gaming boards, and doublecheck by installing Steam and loading up something heavier from your library if you have any.

Having just finished a DRM unencumbered version of Returnal by the excellent “LinuxRulez!” (linux repacks with all the trimmings) i can tell you that what you’re experiencing isn’t normal.

Still would like it to just use the width of the window though.
I know that it’s become a popular “style” for some reson, but it wastes SO much space. Especially on wider/higher res monitors.