Everyone has a preference on how their toast is toasted. Some like it lightly toasted and others want to eat a piece of charred black bread (is it still even bread at that point?). Fact of the matter is this. Your toaster does not care about your desires and feelings.
All toasters give you buttons to press or a knob with options, it’s all the same thing. You put it on “Light” it will come out medium or dark. You want it more well done, it’ll likely come out light. I can’t explain it, it can’t be fixed. The more expensive the toaster, the more things stay the same. But relax. Take a deep breath. Spread that butter all over the toast and all is well.