Please Help! “Recording Audio Through Headet” (But It's Not)

[Android Central Question]

So I bought a lavalier mic that plugs right into the audio jack and for some reason it won't record the audio. It's not the mic as I tried it on other phones and it works fine. On my phone it says that its recording through it, but its still recording through the built in microphone. What's wrong? My phone is an S8+