Same issue it happen with my s8 plus now it happen to my s9 plus very disappointed call tmobile send me a new one but why Samsung take my money again right
I had the same problem with the incall volume being low and not being able to hear the other party read everyone's advice on here to clean with a toothbrush and it worked!!!!!
Oh my God.
I phoned EE, had to factory reset, try SIM in a different phone and was about to send the phone back for repair.......then I tried this and in ten seconds its booming!!!!
I had this low incall volume problem with my current S9 and previous Samsung phone. Last time I just plodded on making calls and receiving them on loud speaker. This time I tried to rectify the problem. Firstly I tried a "soft reset" to no avail. Then I got EE to send me a new SIM card and then volume got a little better but not perfect. So I got a tiny brush and cleaned the speaker at the top and then the speaker at the bottom and VOILA....bloody perfect!! My SIM was 3.5 years old so maybe it had just run its course but I think speakers definitely clogged too.
Where you would place your ear at the top of the phone, there's a tiny mesh earpiece measuring 1cm wide by about 1.5mm tall. .The oil from your skin and wax from your ear clog this up.