Hello, i have Blackview Crown phone. I have problems in my video recording audio and It also my call audio very low! what should i do?

1.to turn up the volume
2.flash the phone
3.If also the same only to exchange it

The sound of his recordings on this phone very low! i think microphone input is low.
what should I do?

another model have the same problem
we had help him solved the problem
may can help you
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