Earpiece speaker not Working but front Camera is

Hi, I recently replacement the screen of a Black iPhone 8 plus. After the screen replacement, everything seemed to be working just fine, but egen I tried to watch a YouTube video I didn’t get sound from both speakers. I then tried to call someone, but I didn’t hear them at all. When I try to take a selfie, the front camera works just fine. Do anyone know what the issue might be, and a solution other than to buy a new flex cable for the front camera and earpiece speaker? Thanks in advance for any answers.