Okay, thank you. I did that and shut it off, and turned it back on. I think it is a bit better. I will have to go outside and see if I can still hear like a normal phone. And yes, you are correct, it is brand new out of the box. Hasn't been outside yet, waiting for my case! Thank you very much.
1) As another person commented try to search for hearing aid settings and play with it on/off. Go to settings>tap on magnifying glass> and type Hearing aid.. - make call and see
2) See if you have VoLTE settings in your phone app's settings or in connection settings. - make call with it on and off
3) Also if nothing helps, don't go through this, just return the device. It isn't worth it.
FYI- On my Note10(T-Mobile) I don't even have to use max volume and in many cases have to decrease the volume as it is loud.
There were couple of thread about the low volume back in September, but don't know what happened and if the issue got resolved or not.
If nothing works take an old toothbrush and clean the incoming speaker even if it looks ok
By the first post it seems that his phone is new and he can still return it to store - so no dirt should of been there that fast