The ringtone and notification volume of OnePlus7TPro mobile phone will not slide.

Enter the settings on the phone. In the settings page, click Input Sound and Vibration. After entering the sound and vibration page, click do not disturb mode on the close page. After turning off the do not disturb mode, you can pull the slider below the bell.

In addition to fast switching mode, unmute. This three-stage switch can also be set. Find the settings on the phone desktop, find the keys and gestures, and select the three-stage switch. Here, you can set three modes.