Follow-up (2026-09-17) — please split this report This bug currently mixes three defects. That is why it has sat in New. Please keep *this* bug for the NVIDIA X11 "output connected, panel dark" failure. I am filing the Ubuntu packaging pieces separately.
Hardware is unchanged: MSI MS-7522, RTX 3050 6GB, no iGPU, two HDMI panels (ONN ONA18HO015C + LG FULL HD). Windows on the same machine is fine. Cables were swapped as a hardware check; the fault follows the Ubuntu/NVIDIA software stack, not a port or panel. Still present on Ubuntu 24.04.4, GNOME X11, driver 595.84, kernels 7.0.0-30-generic and 7.0.0-31-generic. === Keep on nvidia-graphics-drivers-595 === Partial failure: nvidia.ko is loaded, nvidia-smi Disp.A On, xrandr shows both HDMI-0 and HDMI-1 connected at 1920x1080, 3840x1080 desktop, but one panel has no TMDS/signal until that output is cycled: xrandr --output <dark> --off sleep 1 xrandr --output <dark> --mode 1920x1080 --pos … This is the proprietary driver failing to enable the encoder at modeset time. Ubuntu cannot fix the blob. Please forward to NVIDIA. === Split out: nvidia-prime === /usr/bin/prime-select: 1. _get_profile() maps anything other than "on" / "on-demand" to "intel". Writing the string "nvidia" into /etc/prime-discrete (which scripts and humans reasonably do) makes `prime-select query` report intel on a machine that has no Intel GPU. 2. enable_profile() returns False with "Error: no integrated GPU detected." even for `prime-select nvidia` on a discrete-only desktop. So the documented way to lock NVIDIA on a dGPU desktop is a no-op. Patch attached in the nvidia-prime bug. === Split out: ubuntu-drivers-common / linux-restricted-modules === linux-image-generic-hwe-24.04 upgraded to 7.0.0-31. The matching linux-modules-nvidia-595-open-7.0.0-31-generic was *not* installed because linux-modules-nvidia-595-open-generic-hwe-24.04 was held (along with the rest of the 595.84 driver stack). Booting 7.0.0-31 then gives xrandr None-1 / simpledrm. There is no Ubuntu kernel postinst hook that installs the ABI-matching linux-modules-nvidia-$series-$kver when a new HWE kernel arrives. Further: apt's candidate for that package is 7.0.0-31.31~24.04.1+1, which Depends: nvidia-kernel-common-595 (>= 595.91.07). The ABI-matching version for the installed 595.84 driver is 7.0.0-31.31~24.04.1 (no +1). Unholding the meta and `apt upgrade` would try to pull 595.91 or fail. Ubuntu should install the modules version that matches the installed nvidia-kernel-common, not always the newest +1. === Local workaround (does not belong in Ubuntu) === A user-level login script cycles the dark HDMI output. A local /etc/kernel/postinst.d hook installs ABI-matching nvidia modules for new kernels. Happy to share, but the packaging should not require that. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2159683 Title: Dual HDMI monitors fail intermittently on RTX 3050 desktop (no iGPU); prime-select reverts, modeset=0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-595/+bug/2159683/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
