When you cannot download any game or app on your Oculus Quest 2, restart your headset, and then resume the download.
Next, whenever the download gets stuck, disconnect the Wi-Fi from within your Quest 2, and reconnect it again after few seconds. Repeat this until the game has finished downloading.
Now, let me explain these steps in details, but first, some basic checks:
1. Your headset should have sufficient free space. It should be at least twice the size of the game you want to download.
For example, if the app or game you want to download is 3 GB, your Quest 2 must have a minimum of 6 GB of free storage.
2. The internet connection should be stable. You can test your network by connecting your mobile phone or laptop to the same network and running a speed test.
Restart your Quest 2
First, restart your Oculus Quest 2. To do that, wear your VR headset and press and hold the Power button on the right side of your headset. This will open the Power menu.
Next, select Restart from the menu.
Once your headset reboots, resume the download and follow the next step.
Disconnect and reconnect Wi-Fi
When your download gets stuck, simply disconnect the Wi-Fi from within your headset. Keep it disconnected for 1 to 2 minutes, then reconnect it again. Resume the download.
To disconnect the Wi-Fi, open Quick Settings. Click on Wi-Fi and then toggle the switch to off. See the screenshots below:
Repeat this every time the download appears to get stuck.
Even though it may seem tedious, this method worked for me and numerous other users who have confirmed it on Reddit.
I hope that works for you. If you have any questions or queries, please ask me.