Tech ping please?
Have you tried to create/use a xorg.conf file to force the 60Mhz freq, rather than rely on automatic configuration?
I’m on Xubuntu 18.04, 8 gigs on an old Optiplex using a Specter TV which the system sees as being 26”.
If I turn off the TV-monitor while Xubuntu is running and then turn it back on it switches from 1920x1080 to 1366x768 and I have reset the display setting back to 1920x1080. I’m assuming that might besomehow related to your situation.
Maybe I missed your mention of it, but what kind of graphics device/card do you use - and are there specific drivers for it?
Sounds like you need to alter your X11 config file and force 60Mhz or force your monitor.
Possible hints to fix:
https://forums.linuxmint.com/viewtopic.php?t=203112
https://www.reddit.com/r/linux/comments/7w4tnv/how_i_got_my_4k_monitor_working_at_60hz_in_linux/
https://delightlylinux.wordpress.com/2017/09/15/how-to-set-the-default-monitor-refresh-rate/
Have you tried switching out that HDMI cable?
Ah, I see you’re using external sound/speakers. As a test - if your display has built in speakers, try seeing if switching to that to play audio and see if you get the video problems. Just to see if you can isolate the issue down to a specific configuration involving the audio.
My smart TV and smart computer and smart Yammy Stereo all try to be smarter than the other and be the 1st in line. I had to read the manual on setting up my stereo. Now I can listen to CDs or watch laser disks separately from viewing a DVD on my desktop, and the TV doesnt default to “ROKU” everytime I turn the TV on after I turn on the stereo to listen to vinyl.
But the TV constantly searches for the DVD and screws up computing in the process so its disconnected from the Stereo (and ultimately the TV) and just gets “cast” via bluetooth to the TV.
I use a CLI program “xrandr” to control my monitors without mucking around in Xorg config. It’s Arandr in the __untus. It should generat a script to put in your window manager startup.
I had that problem once and ended up swapping distros to fix it. I don’t remember what the distros were though.
right after you boot up and see the lines,
(with the lines visible on the screen) run this:
#!/bin/bash grep modesetting /var/log/kern.log > vid grep Modeline /var/log/Xorg.0.log >> vid xrandr >> vidand then show us "vid"
I don’t have a NUC but I do run Linux on Intel GPU.
The xorg.conf route sounds like it has potential for you.
If your system has ‘updatedb’ running periodically you can use “locate xorg.conf” and it will show all instances of ‘xorg.conf’ on your system.
The X11 log file is
/var/log/Xorg.0.log
Some more things to try. (Might not work, I don’t run Mint kernel)
To switch BACK TO X11 from the console use “Alt-F7”
To switch to the console that X started from you can try “Ctl-Alt-F1” (common for Alt-F1 thru Alt-F6 to be consoles, probably waiting at a login prompt)
That may allow you to see what X11 thinks is happening.
There is also “dmesg” that may provide some details from the kernel/driver perspective.
The ‘challenge’ is probably that the kernel supports both DRM and FrameBuffer for display, and so does the Intel hardware.
You can force your intentions on a generic distro kernel by adding Intel driver instructions to the kernel command line in Grub(or lilo) config.
https://duckduckgo.com/html?q=NUC%20kernel%20command%20line
Another option is config/compile a new kernel with options tailored to the NUC hardware. You can have many kernels available at boot(IF YOU PLAN AHEAD) so fallback is trivial.
Beware the internet instructions for the uninitiated, you can end up with nothing but a command line and few clues how to recover. After the 3-4th re-install you’ll get quick at it and figure out different methods of recovery.
One thing I do while troubleshooting X11 is boot to console and ‘startx’ manually. That way I can “Ctl-Alt-Backspace” to kill X11 and have a working console without rebooting.
YMMV
:)