How to prevent vibration of calls from one contact? I have a contact who calls me regularly on Wednesday evenings. 
I already set her ring tone to "nothing", but cannot find any method to prevent the vibration. 

Using regularly silent-mode, but I cannot keep on when working so it is not an option. 

Wanted result: mute and turn-off for calls of one contact

Phones: OnePlus 3T and Samsung Galaxy S8
OS: Oreo
You can't do it without third party apps. You can try apps like "Good Vibration"