If the OnePlus 6 is in vibration mode, you may not feel any notification such as calls or SMS.
The phone may vibrate, but the vibration is so low that you hardly feel or hear it when the phone is worn in your pocket or lying on a surface.
First of all, we would like to point out right at the start that the vibration intensity of the OnePlus 6 is very poor compared to other smartphones.
In order to get the maximum vibration intensity on the OnePlus 6, please check the following setting:
1. Open the settings on the OnePlus 6
2. Navigates to "Sound and Vibration
3. Goes on to "Vibration Intensity"
4. Sets the slider to the maximum vibration - Done!
Now your OnePlus 6 will vibrate with the maximum vibration, which admittedly is not very strong.
Unfortunately, there is no other option but to switch to another smartphone model.