I have installed an app to directly test the vibration function, same result no vibration at all.
I have reset the phone to factory defaults, same issue here, no vibration at all.
The second issue is the speaker as already often has been complained. I have ordered an exchange speaker from Blackview directly in Janunary and I am still waiting for the part. I have to admit that I am not pretty amused about the qualitiy of these "low level" parts.
The phone is now 5 months in use, sepeaker breakdown after 3 months and now the vibration motor after 5 months, not quite a good reputation for a so called ruged smartphone

Details:
Blackview BV6000
Android 7.0 Built BV6000_Blackview_V01_20161216