I have found on two distributions now (Nobara and Zorin, so different families, too) that an RTX 5090 doesn't get along well with the proprietary Nvidia driver. Nobara kind of self-destructed, and Zorin always used llvmpipe. The quick and easy fix on a new installation is to use the Additional Drivers tab of the Software & Updates utility and choose the current version's "open" driver. As of this writing, that's Nvidia driver (open kernel) metapackage from nvidia-driver-570-open (proprietary).
I also had problems with the official Nvidia installer when choosing proprietary, and did not when using the MIT/GPL version of the kernel modules, so I suspect this is on Nvidia's end. It wouldn't surprise me at all, given that latest is still 570 on Linux, the first major version to support 5090s. (I'm currently using Nvidia's installer because DKMS support isn't available in the graphics-drivers PPA for kernel 6.14.6 it seems.)