Problem:

VoLTE calls are disabled for the primary SIM card. With Do Not Disturb feature enabled, missed calls and notifications still display on screen.

Cause:

After the Do not disturb function is enabled, the call will be automatically rejected if your phone is not connected to mobile data or Wi-Fi. The call notification will also not appear on the screen when you are gaming. After you exit the game, you can check the missed calls, which is the same as when VoLTE calls have been enabled and the phone is connected to Wi-Fi.

Solution:

When VoLTE calls are disabled for the primary SIM card, enable Mobile data and the Do not disturb feature so that incoming calls will not appear when you are gaming. Missed calls will also not be displayed.