I’m surprised it’s not also distorted. Those two tend to go together.
There is no convenient software fix. I used a Behringer UCA-202 stereo adapter.
It’s a good combination of high quality and low cost, and it’s certified for overdubbing in case you want to sing all three Andrews Sisters by yourself. I have two.
It’s not the only one.
https://forum.audacityteam.org/t/sound-card-reviews/8375/1
Koz