This reddit thread helped me a lot with fine-tuning output & input audio profiles: https://www.reddit.com/r/Ubuntu/comments/j61x0f/stock_2004_why_does_my_sound_input_always_change/
Basically like the top comment says:
sudo apt install pavucontrol
Open the program (pulseaudio volume control) and navigate to the rightmost tab (configuration). Find the device there, click the dropdown menu that says “profile” and choose “off”.