QString with 0xFEFF at first position

const char32_t testValue = 65279; // 0xFEFF ZERO WIDTH NO-BREAK SPACE
QString str = QString::fromUcs4(&testValue, 1);
qDebug() << "size: " << str.size(); // result: 0

QString str2 = QString::fromUtf8("\uFEFF\u0041\uFEFF");
qDebug() << "size2: " << str2.size(); // result: 2 ... why not 3?
qDebug() << "str2: " << str2; // result: "A\uFEFF"