Weird Linux Display issue

Some time back I retired my old Pine64 Media Center. I replaced it with an Intel NUC cube which I'd loaded up with 16GB of RAM and a 1TB hard disk. Soeed isn't really an issue with this system, so I went with spinnign platters rather than an SSD. I installed Linux Mint XFCE4 on it along with all of my music (90GB) and vids of various movies and cartoons I've ripped over the years.

Everything is working great, and in fact, today I finally made it all the way through my first complete pass through my music library. However, there is one issue that I'm having that I haven't been able to figure out how to actually 'fix', rather than just work around.

A little more background on my setup that I believe is influencing the issue is probably going to be necessary. The NUC is plugged into my stereo via an HDMI cable from the stereo, it goes to the TV. Obviously, the sound goes direct to my 5.1 speaker setup, but the video goes to the TV.

In the morning, if I turn the TV on to start the music, the screen comes up with vertical lines on top of the desktop image. It looks like this ...

fuzzypic

The screenshot above is a little more fuzzy than it would normally be because I had to use my phone to take the picture, since a screen capture on the device itself shows just a clean desktop. The program in the image above is the Display configuration application. You probably can't read it, but when the system does the autodetect of the monitor as it detects the video refresh rate, for some reason it selects '59Mhz'. If I select the '60Mhz' setting in the pulldown, and then select 'apply', the screen clears up and everything looks normal...

Clean image

If I now turn off the TV, and then turn it back on, everything comes up clean. It appears that the problem only kicks in after the operating system thinks the monitor should be put into hibernate mode after inactivity.

I'm almost positive that if I were to connect directly to the TV from the NUC it would work fine. The sync up on the display takes a few seconds when/if I turn the stereo off and on, so it would appear that the autodetect stuff is being influenced by having the stereo as an intermediate device.

So that is a lot of verbiage just to say that I'm looking for a way to force Linux to sync the refresh rate at 60Mhz. I've looked all around the configuration stuff in /etc and can't seem to find where this is controlled. Again, I'm running XFCE4, so I'm not sure if there is an issue with that or not, but I don't particularly want to reload the box to a different Mint flavor.

I suspect that something in the systemd voodoo is interfering, but I honestly do not know enough about systemd yet to be able to figure out how to force things.

I'm hoping that someone here might have an idea or two. If not, I'm cool with having to adjust it on those rare occasions that I need to turn on the TV to actually do something at the console. Most of the time, the system pretty much runs effectively headless.