M2 MacBook switches off in clamshell mode

Hello,

My wife and I both have the same monitor (LG34WK95U-W) and we use it with our respective MacBooks. I have an M1 MacBook Pro, while she has an M2 MacBook Air.

Recently, her MacBook Air has started shutting down when in clamshell mode while connected to the monitor at her workplace. The MacBook is connected to the screen and simultaneously charged via USB-C, with a Bluetooth keyboard also connected. Previously, this setup worked perfectly fine, but now it's experiencing issues.

Interestingly, this problem only occurs with her MacBook and this particular monitor. All other combinations of computers and monitors work fine in clamshell mode. E.g.:

• my MacBook works without any issues in clamshell mode when connected to her monitor and
• her MacBook works fine in clamshell mode when connected to my monitor.

We have attempted several troubleshooting steps, including unplugging the monitor, restarting the MacBook, enabling the "Prevent automatic sleeping on power adapter when the display is off" option, and using the 'caffeinate' command in the terminal.

However, none of these solutions have resolved the problem.

Is there any way to reset the M2 MacBook and make it forget the screen settings? As I understand it PRAM reset is no longer possible on Apple Silicon.

If you need any further clarification or have any suggestions, please let us know.

Thank you for your help