Animator prevents changing UI Image source image

I’ve got a prefab with an Animator component which contains some Animations which just alters Rect Transform component scale property.

Also in my codes I want to change my object’s image using Image component. I tried this:

public Sprite NormalSprite;
public Sprite SelectedSprite;

private bool _hasLetter;
public bool HasLetter
{
    get { return _hasLetter; }
    set
    {
        if (_hasLetter == value) return;
        _hasLetter = value;
        this.transform.GetComponent<Image>().sprite = _hasLetter ? SelectedSprite : NormalSprite;
    }
}

This works if i deactivate the Animator component. But when Animator is active, it somehow prevents changing sprite image.

Does someone have a workaround for this or maybe anyone could explain the reason?

Thank you

Basically the animation is changing it every frame the animation is running. If you have it set in one animation it will look for it in all your animations, even if it isn’t set during that animation. If not set it will stay at default, or where it was.
Both are doing their job, but Animation comes after Start() or Update() .You can use LateUpdate() to change things after Animation has updated.
Your script is likely working correctly, but your animation is just going and changing it back.
So i think you disable your animator first and then change the sprite.