MacBook Recognizing Wrong Monitor

nmc-iv wrote:

I am using my MacBook Air (M1, 2020) with a Dell docking station (WD19S). The Dell docking station is work-issued, and I also use it with my Windows work PC.

I know that my particular MacBook can only support one additional external display, but my question is as follows: When presented with more than one display option via a docking station, how does my MacBook decide which monitor to display resolution options for?

Because that configuration is unsupported, the answer to that question is not defined. Any behavior pattern you might see would not be guaranteed, and could potentially change as the result of seemingly small configuration changes or system updates.

As you can see in the screenshot included below, my MacBook always selects my Dell E178WFP monitor when I connect to my docking station. This does not include a resolution option for 1920 x 1080, which is my desired resolution on my primary monitor (LG IPS FULLHD).

It seems that you have already learned what the answer is – at the moment – for your particular configuration, and do not like it. As a practical matter, if you want to be sure that the Mac sees the "right" display, you need to plug in just the one external display that the Mac supports. As a start, you could try turning off the monitor you don't want to use, so that only one monitor is turned on and able to report its identity to the Mac. If that isn't enough, you can proceed to unplugging the undesired monitor when you are going to use the dock with the Mac.

I suspect there is some sort of "ranking" going on in the background that is causing my MacBook to prefer the Dell E178WFP over LG IPS FULLHD. I am looking for any information to help me understand what that logic may consist of and how I can potentially influence the monitor preference.

Is the preference based on display connection type (i.e. hdmi vs. vga)? Is it as simple as alphabetical sorting (Dell vs. LG)? Something entirely different?

This is a user-to-user forum. Apple engineers who have access to the information you seek are not here.