Apple EarPods USB-C mic not working on iPhone 15 Pro Max

Recently purchased Apple EarPods usb c type . Audio works well, both with Apple Music, YouTube, and phone calls - everything I've tried on the phone; however, people on the other end of a phone call can't hear me. Also, no sound registers on a voice memo when using the EarPods. I have no case on the phone, so I think the connection between the EarPods and the phone is solid and mic works well in the mic testing websites but fails to work on applications such as whatsapp and games like PUBG.

Any suggestions please?

[Re-Titled by Moderator]