In general, this is a failure of the material and not of the software, but to avoid a return that immobilizes your device for 10 days, we invite you to verify that it is not excessive dust.

Tip: With a slightly damp toothbrush, scrub the affected area (speaker, microphone, sound output for calls next to the front camera).

We hope we have solved the problem, otherwise we will open a request. To do this, we invite you to consult our article dedicated to this topic.