2D sprites don't detect collision

Hello!

So I have 2 2D sprits with both box collider and rigidbody attached and for somereason when they collide the function OnCollisionEnter2D is not working.

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Relevant part of the script:

function OnCollisionEnter2D(coll: Collision2D) {
	Debug.Log("HIT!");
	}

Does anyone know why?
Thanks in advance:

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