Thanks.
Good work on troubleshooting, Dale
Still sounds like a fault with the driver. With both cables going to the same monitor, the driver should recognize that it is the same monitor, and not display both, or it should disable the "lesser", analog connection, I would think.
...
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Yeah, it would be logical to think that - but the driver has no way to know that it's the
same monitor. It might just be another monitor of the same model. (Model and capabilities are usually reported, but very seldom the serial number). And "both" monitors are turned on.
Modern cards and drivers recognize when a monitor is turned off, but that doesn't help at all in this case.
Monitors, of course, are set up to resolve this situation (if they have 2 or more inputs). There is always a manual setting
in the monitor control panel to select which input to use. And sometimes an automatic "priority" to the highest quality input, which can be manually changed. That's a
feature so that you can toggle back and forth between 2 completely different input sources.
That's (partly) why I suggested that the "Identify" button be used.
JamesGreystone, if you're curious, you could see what happens if you disconnect the spare cable
from the monitor but leave it connected to the card. If you're lucky, everything will still be fine.