When dose move constructor and default constructor called [duplicate]

I have this code

class MyString {
    public:
        MyString();
        MyString(const char*);
        MyString(const String&);
        MyString(String&&) noexcept;
        ...
};

String::String()
{
    std::cout << "default construct!" <<std::endl;
}

String::String(const char* cb)
{
    std::cout << "construct with C-char!" <<std::endl;
    ...
}


String::String(const String& str)
{
    std::cout << "copy construct!" <<std::endl;
    ...
}

String::String(String&& str) noexcept
{
    std::cout << "move construct!" <<std::endl;
    ...
}

In main()

MyString s1(MyString("test"));

I thought result would be this:

construct with C-char! <---- called by MyString("test")
move construct! <---- called by s1(...)

But what I get was this:

construct with C-char! <---- maybe called by MyString()

The steps what I thought

1. MyString("test") construct a rvalue by using the constructor with char*
2. Construct s1(arg)
3. Because of arg is a rvalue, s1 should construct by move constructor But I find move constructor won't be called without std::move.

Why is that happening?
How to use move constructor without std::move()?

Compiler:
Gnu C++ 9.3.0