I am wondering how the AMD RX-470 GPU determines its monitor numbers. I assumed it was by port, but testing proves otherwise.
Problem: I purchased a pen tablet monitor for illustration (Huion GT-156HD) and am using 3 monitors. This screen requires monitor 1 status for pen to function correctly.
-proprietary split wire with hdmi, power and usb.
-2x hdmi ports
-the proprietary Huion hdmi (must use, but can adapt)
-2x hdmi to display port wires
-a hdmi to diplay port adapter
Ports on AMD RX-470
-2x display port
Attempted: I've switched monitors from port to port, using various wires and adapters. One time my Huion booted as monitor one, but within a few minutes it reverted to monitor 3. Regardless of configuration, my ultrawide winds up as monitor 1, the samsung as monitor 2, and the Huion as monitor 3. The Huion is of course set as the primary in the windows display settings.
Working solution: I boot my machine with only the Huion connected, then plug in the other two monitors. Although the Huion then reverts to display #3, the driver functions correctly. Difficult to do this on every single boot.
Note: This is a known issue with Huion multi-monitor setup. According to their forums there is a 50% chance that its drivers will be compatible with your GPUs multi-monitor setup. ie within the Huion driver it allows you to select the "active area" however with this GPU regardless of the monitor selected it only draws to display 1.
So, how it the display number determined? Resolution? The order in which it connects (i/o speed)? is the port number some how involved? I really sort of need the functionality of those monitors while illustrating, and it messes up the work flow of other projects that I have minimized. Pulling my tower out on every boot and plugging/unplugging will likely break something with time.