Unable to get name of derived class on C++ side

I have a class extendible in Python like this:

class Task_py : public Task_plugin {
public:
    using Task_plugin::Task_plugin;

    void set_id(int id) override {        
        auto class_name = py::cast(this).get_type().attr("__name__").cast<string>();
        ...   
    }
    
    /* Trampoline (need one for each virtual function) */
    void pre_process() override {
        PYBIND11_OVERLOAD_PURE(void, Task_plugin,pre_process, );        
    }

    void process_frame(const Frame_info& info) override {
        PYBIND11_OVERLOAD_PURE(void, Task_plugin, process_frame, info );        
    }

    void post_process(const Frame_info& info) override {
        PYBIND11_OVERLOAD_PURE(void, Task_plugin, post_process, info);
}

...

py::class_<Task_plugin,Task_py,std::shared_ptr<Task_plugin>>(m, "Task_base"){
...
}

set_id() itself is not exposed and used internally to extract the name of derived class defined in Python on C++ side. This crashes with segfault on the .cast<string>(). py::cast(this).get_type().attr("__name__") works but then I can't convert it to string - it crashes whatever I do.

Interestingly, this works with no problems for simple classes:

class AA {
public:
   void doit(){
       auto class_name = py::cast(this).get_type().attr("__name__").cast<string>();
       cout << class_name << endl;  // Works with no problem
   }
};

py::class_<AA>(m,"AA")
            .def(py::init<>())
            .def("doit",&AA::doit)
    ;

This works and prints class name.
What should I do get the name of derived class correctly?

Start by reproducing the reported difference between the simple AA class and the Task_plugin/Task_py trampoline using the snippets in the issue. Inspect the py::cast(this).get_type().attr("name") conversion path and determine why casting to C-string crashes for the derived class; done means identifying a safe supported approach or a minimal reproducible cause.