Runtime crash when calling SIDE MODULES functions / class methods implemented inside .cpp

[alienself]

Hi I am experiencing a serious runtime error when calling function or methods inside side modules implemented inside .cpp files (working when function / method body inside .h)

I am using emscripten to create one main module and two side modules (dynamic libraries).

I use the main module to open and load the two side modules, I can call functions and class inside the side modules across modules HOWEVER if a function body or class method is implemented INSIDE a .cpp, I get this error:

Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'apply')

Did I forgot something or is this a emscripten bug?

I am missing a flag or something? I tried adding EMSCRIPTEN_KEEPALIVE inside the .cpp class method but no luck

class MySuperClass {
public:
    MySuperClass() {
        std::cout << "MySuperClass!" << std::endl;
    }

    void callMeHere() {
        std::cout << "callMeHere!" << std::endl;
    }

    // cannot be called by other module...
    // TypeError: Cannot read properties of undefined (reading 'apply')
    void callMeThere();
};

.cpp of side module

void MySuperClass::callMeThere() {
    std::cout << "callMeThere!" << std::endl;
}