The user is experiencing an issue with Unity simulation not working properly when using Meta Quest 2 with Link on a PC. After starting the simulation in the Unity Engine, the screen turns solid with an hourglass icon in the bottom left corner, and the Oculus remains stuck until the simulation is ended in the editor. The user has checked for updates and found a version mismatch between the Oculus (v2.1) and the PC app (v85), despite both being up-to-date according to their respective stores. The user has tried troubleshooting steps including reinstalling the Link PC app, factory resetting the Meta Quest, switching cables and Oculus devices, and ensuring sufficient storage space on the PC. The issue seems to have started after updating the Oculus and Link app, as the user was able to use the simulation without issues two days prior.