newcclosure issue in metamethod hooks

Hi, my newcclosure works fine but when used in a metamethod hook it suddenly starts causing a lot of lag and a crash in the game.

I don't know why it happens so I'd appreciate some help.

btw i already confirmed it is newcclosure thanks to some testing.

int newcclosurehandler(lua_State* ls){
	auto nargs = lua_gettop(ls);

    // we dont wanna copy the args so we insert the func at the top ;
    lua_pushvalue(ls, lua_upvalueindex(1));
    lua_insert(ls,1);

    int status = api::rlua_pcall(ls, nargs, LUA_MULTRET, 0);

    if (status && strcmp(lua_tostring(ls,-1), "attempt to yield across metamethod/C-call boundary") == 0) return lua_yield(ls,0);

    return lua_gettop(ls); // return all results
}

int newcclosure(lua_State* ls){
    luaL_checktype(ls, 1, LUA_TFUNCTION);

    if (lua_iscfunction(ls, 1)) {
        return 1;
    }

    lua_pushcclosurek(ls, newcclosurehandler, 0, 1,0);
    auto ncl = ((Closure*)lua_topointer(ls, -1));
    ExecClosures.insert(ncl);
   
    return 1;
}