question on properly managing reference members in a local class in C++

Question

Is the reason why I got a garbage value because of the following or am I wrong?

the Other object o passed as an argument to the Inner constructor, goes out of scope after the Inner object has been created, but before the end of the get_a_value member function. Therefore, the reference member m_o in the Inner object becomes a dangling reference, referring to an object that no longer exists.

#include <iostream>

class Other
{
private:
    int j = 3;
    friend class TEST; //class TEST is a friend of the class Other
};

class TEST
{
private:
    int i = 10;
public:
    int get_a_value() const //a member function of TEST
    { //member function begins
        struct Inner

        {
            Inner(Other o) : //constructor
                /*m_o{ o } it is correct too */ m_o( o )
            {
                std::cout << "o.j " << o.j << '\n';
                std::cout << "m_o.j " << this->m_o.j << '\n';
            }
            int get_other_value() //other in the name of the member function refers to Other class defined above
            {
                return this->m_o.j;
            }
            Other& m_o;
        };


        Other o; //local variable of member function get_a_value
        std::cout << "outside o.j " << o.j << '\n';
        Inner i(o); //local variable of member function get_a_value
        return i.get_other_value();
    }//member function ends

};


int main()
{
    TEST t;
    std::cout << t.get_a_value() << '\n';
}

The output of code above is :

outside o.j 3

o.j 3

m_o.j 3

623661