Anyone having issues with their IPhone 7 plus?? People struggle to hear me and also not all videos have volume when wathcing them on facebook??? is this common?
It seems a bit strange. I would suggest you to perform a factory rest on your phone (https://support.apple.com/en-nz/ht201274) to see if this resolves your issue.
You can call Apple on 00800 7666 7666 if the factory reset doesn't work for you.