[Bug...?] Cannot detect attached monitors

[AkariiinMKII]

There are two verified situations cause the command line returning Monitor: None in results

Monitor(s) powered off

In this situation, you will get Get-CimInstance : Not supported when running

Get-CimInstance -Namespace "root\wmi" -Class WmiMonitorID

and

Get-CimInstance -Namespace "root\wmi" -Class WmiMonitorListedSupportedSourceModes

Just turn on the monitor and try again.

Unexpected permission error

Directly sign in with Microsoft Remote Desktop app, aka RDP client, after system boot up, may cause unexpected permission error. This has been reproduced on my machine (Windows 11 Pro, version 10.0.22631, 64-bit).

In this situation, you will get Get-CimInstance : Access denied when running

Get-CimInstance -Namespace "root\wmi" -Class WmiMonitorID

and

Get-CimInstance -Namespace "root\wmi" -Class WmiMonitorListedSupportedSourceModes

Meanwhile, running these commands with admin privilege returns expected content.

To solve this, you need to sign in on the machine first, and then switch to RDP client.