Visual studio 2017 c++ if and else statements are not executed.

When you are coding a red black tree and debug granpa!= nullptr even though it is true, the entire phrase is skipped. I stopped it in debugging mode and checked it by pressing f11, but I only ran the line with if and else, and ignored all the codes inside. What's wrong with this?

if (granpa != nullptr) {
        if (granpa->left == parent) {
            granpa->left == n;
        }
        else if (granpa->right == parent) {
            granpa->right == n;
        }
    }
    else {
        root = n;
    }