ALT won't centre my elipse. Very confused Beginner

So, every time I try to hold alt and click where I want, or click and then hold alt, no matter what I do, the ellipse tool will never begin from that point. Instead, it always chooses a corner of the pink square from the locked, template layer, or a little off the red mark, never inside the red mark. However, making the larger circle was no problem, maybe I was just lucky. But it leaves me super confused.

Thanks