So I was trying to make something unrelated to the problem, and came upon a weird thing in TS. If I create a type for example:

type A = "A" | "B" | "C";
type C = {
  variable: A;
}

I can create an object of type C while providing the value of variable with a string literal "A" like so:

const OBJ: C = {
    variable: "A"
}

But when I create a class implementing C I have to do "A" as A, "A" as "C" or "A" as const when assigning variable default value;

class O implements C {
    variable = "A"; // throws error `type string is not assignable to type A`
}

Why is that? Is = "A" inside of classes treated differently?

TS Playground link