Happened to me too.
I've done 3 resets so far because resets seemed to have fixed it for some odd reason which would indicate a software issue however this last reset has not.
I need to return this thing because now it's even doing it barebone stock.
The ear speaker in call is completely non-functional, only the external speaker works when you enable speaker phone.
And no, I'm not stupid or phone illiterate, It's not on mute or anything ridiculous like that.