P53 with Quadro RTX 3000 gpu

Has only occurred since early Nov 2020, which is when the latest Thunderbolt/Dock firmware was installed

• Have two external monitors connected via HDMI cables.
• System Update has installed all drivers/firmware
• Latest nVidia and Intel graphics drivers
• Have replaced HDMI cables
• Have replaced Thunderbolt 3 Workstation Dock Gen 2
• Have reflashed Thunderbolt and Dock firmware on both Docks
• Have disabled FirmwareSwitchService, per other threads' suggestions

Scenario 1:  Both external monitors connected via Thunderbolt 3 Workstation Dock Gen 2.  Laptop screen open and in use (3 screens total)

Symptoms:  Both external monitors blink off randomly for 5-10 seconds at a time.  Particularly when Chromium Edge or Microsoft Office products are open.  Frequently must unplug monitor to get it to turn back on.  Symptoms MUCH more prevalent in the PM than in the AM.

Scenario 2:  One external monitor connected via Laptop HDMI port.  One external monitor connected via Laptop Thunderbolt port (using USB-C to HDMI adapter).  Laptop screen open and in use (3 screens total)

Symptoms:  For monitor connected via Thunderbolt port, no change from Scenario 1.  For monitor connected via HDMI port, no blinking, no turning off.

Scenario 3:  One external monitor connected via Laptop HDMI port.  One external monitor connected via USB-C (non-Thunderbolt) port, using USB-C to HDMI adapter.  Laptop screen open and in use (3 screens total)

Symptoms:  For monitor connected via USB-C port, still have blinking, but it is much shorter in duration-- 1-3 seconds, and the monitor never stays off as it did in Scenarios 1 and 2.  For monitor connected via HDMI port, no blinking, no turning off.

Per another thread, when I visit the following websites, the monitor connected via the USB-C adapter will turn off and stay off until I close the tab.  This happens regardless of which monitor the tab is open on.

https://abc7.com/health/la-county-health-director-consider-a-virtual-thanksgiving-dinner/8222844/

https://abc7.com/sports/boxing-legend-oscar-de-la-hoya-talks-possible-comeback/8052211/

Nvidia Control Panel reports both my monitors are HDCP-compliant (and functional).  Neither monitor has an issue opening the above sites when connected to another PC, and the blinking/turning off only occurs with this P53.

Please advise.

As an update, the following scenario results in no blinking on either external monitor:

1 external monitor connected via on-board laptop HDMI

1 external monitor connected via VGA cable connected to USB-C to VGA adapter

This really looks like a Thunderbolt and/or digital video problem.  

As previously stated, it did not occur until I updated to the latest Thunderbolt/Dock firmware.

Using a DP-DVI or HDMI-DVI adapter somewhere along the cable (either on the dock or on the monitor) also fixes this for me.  

I think it's an HDMI-CEC issue as when I connect a TV, the TV actually gets turned off instead of blinking/going into standby.

Using Microsoft Office or Edge full-screen exacerbates the issue.  Simply maximizing a Word or Excel window is enough to immediately turn the monitor off.

You mind sharing how you downgraded the DP firmware?  That's something I'd like to try.

Can also confirm that other manufacturer's models are also having issues similar to this as well.

I did this a couple of months ago. If you dig into firmware update tool directory, you will find executables for single components. Just find the one for DP hub and execute it from command line with proper arguments.

The most tricky part is to find old versions of firmware update bundles. Fortunately changelog lists those names so one can find it via google dorks.