Razer Blade 15 GTX 1060 -- Thunderbolt 3 /USB-c not working

Hi all! I have a the aforementioned Razer Blade 15 with the GTX 1060 that was released back at the end of 2016. For a long time I used the Thunderbolt 3/USB-c port to connect to an external monitor. I use a usb-c to display port cable. Recently this set up just stopped working. When I connect the cable, the blade recognizes that a monitor has been attached and "extends" the screen, but the external monitor just shows black. I can move my mouse off the laptop screen, but still only black on the external monitor. In the meantime, I have switched to connecting to an external monitor via HDMI. I have tried updated all my drivers manually and via the GeForce app. I have tried scouring the support forums here, but have found no solution. Has anyone seen this issue or know how to debug it?