I can't use monitoring

I'm trying to record a song and as always, I use the monitor so I can't actually hear my voice on the heaphones. Turns out it's not working.

When I pick an effect like "deeper voice" or "helium breath" it DOES work but as soon as I select "no effects" (it's what I want), it doesn't work again.

Does anyone know what I should do? Because honestly, it doesn't make any sense!!

Thank you!