Scrambled video after locking

[qhartman]

Note that I'm not currently actually using the respin, but I have lifted just about everything from here to manually configure my Ubuntu 18.04 install on my 9560. Hoping you guys might have some insight into this. I have my kernel pinned to 4.13 so that I can keep using bluetooth devices without interrupt load. I am only using Nvidia video. No fancy switching or anything. I work plugged in at a desk 90+% of the time so the extra power consumption isn't a concern.

Since upgrading to 18.04 from 17.10 I get inconsistent behavior with video when returning from a locked session. I have my laptop connected to a 4k monitor through HDMI. I use the laptop internal screen as a secondary monitor. I get up from my computer, lock the screen, and both screens go blank after a few seconds. All as expected.

However, when I come back, now I sometimes get that screen config back, and sometimes it doesn't seem to detect the external monitor at all. If I manually reconfigure the displays, it will behave as normal, sometimes I can just unplug and replug the HDMI and it will go back to normal.

The worst though, is that sometimes I get this rolling scrambled image on my monitor, and if the machine comes back in that state, nothing but a hard reboot will get it out of it. This is happening with increasing frequency and I'm concerned that it's a hardware problem, but I haven't puzzled out a good way to test that since the behavior is inconsistent as far as I can tell.

Any thoughts or similar experiences? I'm thinking about wiping the machine and reloading from the respin directly to see if that has any effect on the behavior, but that would be a lot of effort to spend if this behavior is something you guys are also seeing.

Thanks!

[stockmind]

Can you post your grub boot flags, xorg config, and the graphic card selected?

[qhartman]

Grub flags:
GRUB_CMDLINE_LINUX_DEFAULT="acpi_rev_override=1 nouveau.modeset=0 quiet splash"

I don't have an xorg.conf

I'm using the Nvidia card (01:00.0 3D controller: NVIDIA Corporation GP107M [GeForce GTX 1050 Mobile] (rev a1)) and driver 390.48