Hi EVGA forums,
 
I have 2 desktops connected to 2 monitors (primary: VG279QM over HDMI 2.0 1920x1080@240hz and secondary: ASUS VG248QE over Dual-link DVI 1920x1080@144hz) and I've been getting intermittent black screens (screen goes black for 1-5 seconds, then the image re-appears) on one of the desktops on the VG279QM (HDMI-connected monitor). The black screens happen somewhat randomly but especially in a few scenarios I've been able to isolate. Specifically the VG279QM will go black for 1-5 seconds and then the image is restored. On very rare occasions, the HDMI signal is completely lost (monitor displays HDMI-1 <input-name> no signal) and I have to either switch input on the monitor or power cycle it until the image is restored.
 
Most often this problem happens when I have 1 or 2 streams/videos playing (Twitch/Youtube/Hulu, etc.) in Chrome/Brave (chromium-based browser) and I open another video/stream or load a 'heavy' webpage in a different window. The problem happens regardless of whether Hardware Acceleration is enabled or disabled in Chrome/Brave. The problem also occurs when using Firefox and happens regardless of whether the new webpage is being loaded/refreshed on the primary or secondary monitor. During this time, the secondary VG248QE connected via DVI always remains on without issues.
 
One page where I can reproduce the issue 100% reliably (regardless of whether I have streams/videos playing) is on NBC's Peacock streaming service: Whenever I load this page the VG279QM monitor always goes black for 1-2 seconds before restoring the image.
 
The full specs of this PC are: i7-4790k (stock 4.0GHz, 4.4GHz boost), 32GB DDR3 RAM running at 1866MHz (CL10), GTX 970 FTW+ Gaming (stock: a couple of 500GB SSDs and a 2TB HDD. Windows 10 x64.
 
The second PC connected to these monitors (both over DisplayPort) is a i9-9900k/GTX 1080ti PC. The black screen problem has never occurred on this PC with the VG279QM monitor. Either over DisplayPort or over several of the HDMI cables I've tried, although I do notice a minor stutter on the VG279QM monitor (e.g., the Twitch stream will stutter for about 0.5s then continue as normal) when trying to reproduce the problem where the first PC would usually black screen. I want to especially note that I've tried both HDMI inputs on the VG279QM and several HDMI cables (2 specifically noted as HDMI 2.0 certified) and was not able to reproduce the black screen problem on the 1080ti PC. Whereas the problem occurs for both HDMI inputs and all different cables for the GTX 970 PC.
 
I've been wrestling with this problem for about a month since getting the VG279QM 240hz monitor. And tried various combinations of drivers (with and without GeForce experience), as well as, different combinations of HDMI inputs and cables, NVidia Control Panel settings (i.e., Using different Content-type reported to the display: Auto-select/Desktop/Full-screen videos), etc. However, the problem persists. Below are the current driver and BIOS version, as well as, some other selective settings and screenshots.
 
Nvidia Driver version (as reported by Windows): 27.21.14.5671 (9/30/2020)
Nvidia Driver version string (as reported by GPU-Z): 27.21.14.5671 (NVIDIA 456.71) / Win10 64
BIOS: 84.04.36.00.71
Screenshot: attached
 
Looking for some suggestions on what I can try next.
 
PS. One suggestion I've seen floating around during my research is to update the card BIOS using `nvflash`. However, it seems that my BIOS version (specifically for the FTW+) is already the latest (84.04.36.00.71) listed on TechPowerup: I'm not sure if flashing BIOS from a different model of the card can potentially brick the card or cause further problems.
 
Thanks in advance.

Clearly there is a problem with the hdmi port on the 970.

The intermittent black screen using the adapter could just be the adapter itself since everything works fine with the 1080 ti.