You are not logged in.
I have an Acer Nitro V15 that uses Intel+Nvidia Hybrid graphics. Recently I've acquired an external LG monitor, after trying to get it to work on the HDMI port, I gave up and bought a simple USB-C hub with HDMI and I'm now using it on the Thunderbolt 4 port, and it solved that problem, but soon I found another one.
On boot, with the monitor connected, the 29" FHD UltraWide shows a message about the resolution being set to 3840x2160, and both my notebook and the monitor only get a black screen, I can change between TTY and reboot, but the issue persists. Running xrandr only returns "Can't open display".
Only by removing the USB-C hub and rebooting and then connecting the monitor it will work as usual. Plugging the hub afterwards shows no issues, the monitor connects with no problems and displays the correct resolution and refresh rate.
If the system sleeps, hibernates or shuts down the screen to save power, if the monitor returns, it will be set to 640x480. The problem is remedied by removing and plugging the hub.
If I connect the hub on the login screen it appears to not get detected, if I then login, I get the same 640x480 resolution. Reconnecting remedies the problem.
When connected to the built-in HDMI port, the monitor would not give an image. Installing xf86-video-intel and enabling nvidia-drm.modeset=1 solves it, but the performance and image quality are terrible. Running only on the dedicated GPU solves the problem too, but the gaming performance is affected greatly and battery life would suffer, this all led me to using the USB-C port.
However, either solution would recognize the monitor on boot and allow me to login, which leads me to believe it is not a problem with faulty cable, port or the monitor. The system also recovered from sleeping and such without issues.
I checked and it appears the hub is not using DisplayLink.
Some System Info
Operating System: Arch Linux
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-arch1-2 (64-bit)
Graphics Platform: X11
Processors: 16 × 13th Gen Intel® Core™ i7-13620H
Memory: 16 GiB of RAM (15.3 GiB usable)
Graphics Processor 1: Mesa Intel® Graphics
Graphics Processor 2: NVIDIA GeForce RTX 4050 Laptop GPU/PCIe/SSE2
Manufacturer: Acer
Product Name: Nitro ANV15-51
System Version: V1.21Offline