pin.Length != 4 || pin.Length != 6true || true = truefalse || true = truetrue || false = true
pin.Length == 6 || pin.Length == 4false || false = falsefalse || true = truetrue || false = trueOR you need to switch it to ANDa == b || c == d -> a != b && c != dpin.Length != 4 || pin.Length != 6true || true = truefalse || true = truefalse || true = truetrue || false = truetrue || false = truepin.Length == 6 || pin.Length == 4false || false = falseORANDa == b || c == da != b && c != d