Whatsapp voice notes cutting out

Why with my iPhone 12 max pro, when listening to a voice note if I pass my hand over the face of the phone with touching the screen the voice note stops? Anyone else find this happens? I spent an actual fortune on this phone and loads of little weird annoying things that don't prevent the phone from functioning are going on. If I bought a phone for £100 I wouldn't mind this, but this phone cost me the price of a secondhand car!