Precision 3520 video glitch

I'm putting this here just in the off case this is a software issue and not a hardware issue.

I have a refurbished Precision 3520 with a 7th gen i5 processor (Kaby Lake). It has the on-CPU Intel HD Graphics 630 and the secondary Quadro M620 graphics. All the applications I use on a regular basis use the Intel graphics.

When I received the computer, I noticed that occasionally the screen would "glitch" -- that is, the screen would display a distorted image around the top third of the screen for only a fraction of a second then it would be fine. This happens under low workloads when the CPU is running around normal temperature.

Recently, the computer has been blacking out the screen completely. The backlight is off and there is nothing on the LCD. Closing the lid and re-opening it bring the screen back (I have the computer set to do nothing when the lid is closed). Interestingly, if I'm using a projector during one of these sessions, my laptop's screen is black but the projector continues to display content.

I found an older article that mentioned that Hyper-V could cause some screen glitching, so I disabled it (stock Windows 10 install). I haven't noticed a completely black screen since (it's only been 2 days) and I am not using any virtualization apps when the screens are glitching. I hope this will keep as-is. I don't really mind the occasional video glitch but the black screen is very annoying.

I have tried disabling the Intel graphics and just using the Nvidia, but I couldn't do it for long because I was teaching a class and needed a projector, and the Nvidia graphics will not display on multiple monitors.

Ideas? Suggestions? I'm about to boot the computer off a Linux thumb drive and work on it all day just to see if the OS or software/driver is the issue.