XPS 13 9380, flickering with external monitor connection

I've posted this on various subreddits and on Tech Support Forum, but thus far, no one has had a solution that works. Of course this issue had to begin right when the extended service warranty on  my XPS 13 expired! Anyone else experienced this issue and found a solution other than updating drivers?

SUMMARY OF MY ISSUE:
For the last couple of weeks, I am unable to connect the XPS 13 to external monitors anymore. As soon as I try to connect to an external monitor, the connection doesn't happen and the built-in screen on my laptop goes black for a second and then starts flashing rapidly until I disconnect from the docking station and/or external monitor. I know the issue is with the laptop, not with the monitors because my work laptop is able to connect to the same monitors without issue.

CONNECTION:
In the past, I would connect my XPS 13 to a VisionTek USB Dual 4K Universal docking station via USB-C cable (my laptop is very slim and only has USB-C ports.) The external monitor would be connected to the docking station via HDMI. As noted above: I'm still having this problem when not using the docking station and instead connecting laptop-to-external-monitor directly (via USB-C to HDMI adapter)

HERE'S WHAT I'VE TRIED DOING:

• Setting laptop to a restore point of a couple of weeks ago when I knew this wasn't an issue
• Making sure all drivers on the laptop are updated (they are -- I have used Dell Support Assist, Dell Update and done the manual installation of the video drivers via Dell.com) -- the issue remains. 
• Tried connecting directly to the external monitor (not using the docking station), by using a USB-C to HDMI adapter -- the same flickering issue and inability to connect happens
• Using the same docking station and/or cables to connect my work laptop to the same external monitors -- all the monitors are working with my other laptop-- so that's why I assume the issue is with my personal laptop
• Tried connecting to the external monitor wirelessly -- this worked, but I want to do a hard-wired connection for better resolution / image quality

OTHER NOTES:

• Note: the USB-C ports do still recognize the power cord when plugged into them
• The laptop is out of its extended service warranty now.
• Honestly, except for this issue, it still works okay, so I'm hoping there's a fix for this issue as I'd prefer to wait a bit before upgrading.

LAPTOP SPECS:

VIDEO:
Video of the screen flickering (immediately after connecting to the port) is included here.