QString::arg() convert floating type to integer

#include <QCoreApplication>
#include <QDebug>

class MyFloat {
    float value;
public:
    MyFloat(float f0) : value(f0) {}
    // Type conversion operator
    operator float() {
        return value;
    }
};

int main(int argc, char** argv)
{
    QCoreApplication app(argc, argv);
    
    MyFloat mf = 5.1;
    auto var = QString("%1").arg(mf);    
    qInfo() << ((var == "5.1") ? "Equal, var value is: " : "Not Equal, var value is: ") << var;
    return 0;
}