Desktop files disappear when connected to external monitor

My Macbook air M2 (2023)'s files disappear from the desktop (i.e., all icloud documents) as soon as I connect the device to a monitor.

This seems to happen intermittently, however, as soon as the external monitor is disconnected they reappear. I have contacted support however they are unable to assist, and the local apple store don't have monitor available to plug it into to replicate the issue