Hey, I posted this in the previous version but you might have missed it - I think there's a math error in your frequency calculations. Using a pure tone generator (https://www.szynalski.com/tone-generator/), the frequencies the app "hears" isn't matching what's being played. For example, playing 100Hz is heard as 48Hz, and playing 800Hz is heard as 121 Hz.
I assume it should be a fairly easy fix, but do lmk if you want any help - I've got Unity and C# experience, and a fair amount of free time atm. Plus a friend who's fairly expert on this frequency/signal stuff who I can bug for help lol.