PyRun_SimpleFile calling multiprocessing Python Class cause endless init loop

[Xeno]

//C++
string path = "C:/PycharmProjects/testProject/test/main.py"
FILE* fp = NULL;
errno_t fp_err = fopen_s(&fp, path.c_str(), "r");
if (fp == NULL)
{
     cout << "[PyScript] Error opening file: " << path << endl;
     return false;
}
// after calling this, the python main class __init__ will loop forever
int re = PyRun_SimpleFile(fp, path.c_str());
fclose(fp);

import ctypes
from multiprocessing import Manager
class TestClass:
    def __init__(self, count):
        self.count = count
        # python will loop here forever, without it the class will run fine
        self.sync_manager = Manager()      

How do I get around this issue on multiprocessing when calling the calss from c++?