Oh no! If you're using the mouse or a touchscreen to drag the slider around, try clicking the buttons on either side of the slider instead, or using the keyboard keys. Sometimes it's easier to zero in on the right wave shape with buttons.
Once in a while, the right value might be very close to one end of the slider or the other, and they can look very similar. If it feels like it's very close, but you're at the end of the slider, try moving to the other end of the slider.
If nothing works, you might've found a bug! 🤓 I just tested the game a couple of times myself and didn't hit any snags, but the wave configurations are randomly-generated (with constraints), so you might've happened upon something I've never seen. Try restarting the game (Esc).
Thanks a lot for giving it a try, anyway!