Simple constant getter is creating a cache miss? (C++)

Question

I am currently benchmarking a program on a Linux system with Valgrind. I have this strange cache miss with the getter method const int GetID() const, but I can't really explain where it came from. Does anyone have any idea what's causing this problem? I thought it might be caused by the constant keyword at the end, but it hasn't changed.

The cache miss occurs in the L1 during the read operation. I have added a screenshot below the code snippet.

class GameObject
{
friend class GameManager;

private:
    int id; 

    GameObject();
    static int CreateID() { return /* do some id stuff in here */}
    ...

public:
    ~GameObject();
    const int GetID() const { return id; }
    ...
};

KCachegrind Screenshot:

UPDATE:

These are methods of the GameManager class that call the const int GetID() const method. It is called when a GameObject must be destroyed or returned to a specific point. The GameManager contains a vector of all GameObjects, they are created when the application starts, after which the vector does not change at all. After they are created, the attached components call the GameObject* GetGameObject(int const _gameObjectId) method once to retrieve all required components. So I guess the GameObjects should already be in the cache or did I miss a point? Maybe the call is so strong that it creates more cache misses at the beginning of the program than the rest of the application at runtime?

void GameManager::DestroyGameObject(const int _id)
{
    for (auto it = gameObjects.begin(); it != gameObjects.end(); it++)
    {
        if (it->GetID() == _id)
        {
            gameObjects.erase(it);
            return;
        }
    }
}

GameObject* GameManager::GetGameObject(const int _gameObjectId)
{
    for (int i = 0; i < gameObjects.size(); i++)
    {
        if (gameObjects[i].GetID() == _gameObjectId)
        {
            return &gameObjects[i];
        }
    }
    return nullptr;
}