Audio message volume goes up and down

When I hold down the audio button and record a message to send to a friend using the messages app, the volume of my voice goes up and down. Like it will start very quiet, then get super loud, then and some point get quiet again, etc.

I have tried speaking into the top of the phone, the bottom of the phone, holding the phone completely still, taking my phone case off, etc.

I recorded messages and sent them through instagram’s messenger and the volume is completely fine. So this leads me to the understanding it is not an issue with my phone, it is an issue with the voice recording of the messages app.

And it won’t let me attach a video here to show the issue... ugh.

but in the image I pointed out the feature I am using. And you can see the wavelengths in the message in blue- I was speaking at the same volume the whole time and you can see there are like no wavelengths at the first half of the message. This is where it plays my voice very quiet. Then it gets super loud where the larger wavelengths are.