Hey there FelixLeMinh! We noticed that your Quest 2 is stuck on a black screen. It saddens us that you are experiencing this issue with your device and we want to help! We see that you have also restarted your device more than once yet the issue still persists.
Since you have tried rebooting the app, we would suggest to perform a factory reset on your Quest 2. Please note that performing a factory reset is irreversible and will remove all account information, downloaded games, and content from the headset. However, it won't remove content you've purchased or downloaded from your account.
To perform a factory reset using your phone:
Open the Oculus app on your phone.
Tap Devices in the bottom menu.
Tap the headset connected to your phone.
Tap Advanced Settings.
Tap Factory Reset and then Reset.
You can also perform a factory reset using your Quest 2 itself. Kindly click here for the procedures on how to do so.
We hope this helps!