Move GameObject with transform.position

Hey,
I just ran into a problem I have six prefabs (all are sprites) with the same scripts on them. (They get randomly spawned).
I realized that one of the prefabs isn’t able to move so I decided to try something:

void Update () {
        int i = Random.Range(-10, 10);
        transform.position = new Vector3(i, i, i);    
}

It works on all prefabs except this one. I get no Errors. It isn’t set to static.
Similar ways like moving with rigidbodies or other commands don’t work too.
Where could my problem be?

They normally do work. If an element accepts integers they cast it by themselves.

Solution: I set one of the Animations to a fixed position. I removed it and everything did work.