2 Monitors Detected, but only 1 displaying picture

[rboerner]

Originally Posted by oldsodacan

I'm on a 2020 MacBook Air. I've got 2 monitors connected via my Plugable dock via HDMI and I can see both monitors are detected when I'm in display preferences and DisplayLink preferences. Both monitors also have a blue light, indicating they're connected.

However, monitor 2 will only display a picture when it is set to mirror monitor 1. Both monitors are the same model (acer XF251Q).

In the screen layout in display settings, monitor 2 is represented as much smaller than monitor 1, but I have not yet found anything I can change to fix that and make the monitor image visible.

Even if I unplug monitor 1, monitor 2 still just a black screen while being detected. Problem persists even if I swap the HDMI ports.

Mirroring monitor 1 on to monitor 2 is currently the only way to get picture.

Based solely on your description, I would suggest replacing the HDMI video cable being used with the affected display in order to rule out the HDMI video cable as a contributor.