Arkanoid-like bounce troubles

I'm trying to recreate a Arkanoid-like game with physics 2D, and it seems to work fine, but whenever the ball travels close to the wall, it sticks to it, so the ball stays bouncing up and down for ever.

I have my paddle with 4 colliders, so depending which hits, the ball will go right or left, but when it gets stuck on the wall those colliders dont work, the ball just keep going up and down.

I've done it applying Rigidbody2D.velocity to the ball, and if it hits with a high enough angle the bounce works fine, but it seems to be a minimum angle until it sticks (and it is not that low, happens often). Help please!