QLocale::toDouble and QLocale::toFloat have different behaviours on various OS

QLocale::setDefault(QLocale(QLocale::German, QLocale::Germany));
const QString englishFloat = "3.5";
const QString germanFloat = "3,5";
bool myOK = false;
/* On my Linux desktop and the Linux build server: result = 3.5, ok = true
   On my windows desktop result = 0, ok = false */
float result = QLocale::system().toFloat(englishFloat, &myOK);

/* On my Linux desktop and windows desktop: result = 3.5, ok = true
   on my Linux build server result = 0, ok = false */
result = QLocale::system().toFloat(germanFloat, &myOK);