I have a couple of weeks old XFX Speedster Merc 319 Black RX 6800 XT and have just for the first time attempted to drive a second monitor off the USB-C port, however this causes several issues:
1. When hot-plugging into the USB-C port the monitor detects sometimes and not others.
2. On the times it detects, the monitor doesn't display until I manually change a setting in the display properties (eg. change refresh rate to 50hz and back to 60hz).
3. There are always sparkles randomly flashing across the screen, like glitter. If I turn the usb-c plug up one way or the other, they are better or worse.
4. On the worse plug orientation, there are also flickering lines appearing randomly across the screen at different heights.
Some things I have tried and noticed:
a. Same issue happens whether I plug into my monitor or my TV, so it's not the monitor.
b. I'm using a USB-C to HDMI adapter, then HDMI to monitor (or TV). Both cables have proven track records. To be sure, I tested them both on a laptop and had no issues whatsoever.
Monitor is 1080p60 and TV is 4K60. Both drive fine when using the plain HDMI output from the GPU.
So... It looks like I got a card with a bad port, then, right? Warranty job?
What is the Make & Model of your USB-C>HDMI Adapter?
Does your Laptop have a USB-C port also like the RX6800XT?
Adapter is unbranded. But like I said, it works fine on the laptop.
The laptop has a USB-C DP port for display output.