I am running Manjaro with KDE on an Alienware m15 R4 and Intel/Nvidia hybrid graphics. I have external monitors connected to both the HDMI and DisplayPort outputs, with the HDMI as my primary monitor, the DisplayPort as my second monitor, and the laptop display as my third monitor. I am running kernel version 5.15.85 LTS and graphics driver version 126.96.36.199.
I ran System Upgrade from Octopi to upgrade to the latest kernel, graphics drivers, and apps packages. I then rebooted and found that my second (DisplayPort) monitor is blank, no display at all. However, the KDE System Settings → Display and Monitor still shows all three of the monitors as before, and lets me change the settings for all monitors, even the DisplayPort monitor.
I have tried several things to get the DisplayPort monitor working, such as disabling and reenabling it, unplugging and rebooting, changing monitor inputs away and back, etc. However, nothing has solved the problem, and the monitor remains inactive.
I finally restored my system using Timeshift and everything immediately started working as before. At this point, I am out of ideas as to what to examine and/or try.
I am running Manjaro with KDE on an Alienware m15 R4 and Intel/Nvidia hybrid graphics. I have external monitors connected to both the HDMI and DisplayPort outputs, with the HDMI as my primary monitor, the DisplayPort as my second monitor, and the laptop display as my third monitor. At time of update, I was running kernel version 5.15.85 LTS and graphics driver version 525.60.11.
This is my second attempt at an update, since I ended up having to roll back the 24 January Stable Update, when my system would no longer operate the DisplayPort monitor. (See my previous post on that.) Initially, I had the same problem with this update, in that after I rebooted and logged in the DisplayPort monitor was black, but still was recognized by the KDE System Settings->Display and Monitor app. (Note that when I reboot or power-on the system, the external monitors are blank until I log in. This has been the case for as long as I can remember.)
However, this time I experimented with the system and found that if I unplug the DisplayPort monitor when I rebooted the system, and left it unplugged until I logged in to my KDE desktop (which configures itself to use the HDMI monitor and laptop monitor), then I can plug in the DisplayPort monitor and the desktop automatically reconfigures itself into my desired three-monitor configuration. After playing around with this for awhile, I found that I just need to unplug the DisplayPort monitor when I am ready to log in to my account and then plug the monitor in after my desktop is up and running, and all will be well.
So, it seems to me that this might be more of a KDE issue than something lower-level, such as drivers. I seem to recall hearing that KDE was working on code updates for detecting and managing monitors for multi-monitor situations. I wonder if this is related to that work.
For now, I can unplug when Iogin as a workaround, but hopefully this can be identified and fixed in a future update.
also gnome is having similar issue. there’s something wrong with the drivers i guess. i really hope someone from the manjaro team could inform us, if the problem has been identified and when will someone (nvidia probably) fix this. currently the entire forum is filled with nvidia hybrid issues.