SpriteKit collision prevent from pushing out - objective-c

Question

I have this problem:
I have node A and node B.
What i want is when collision between them happens (node A collides with the top of B), node B won't be pushing node A a bit up. Because as it is now, when A collides with B, its being pushed back a bit, and collision instantly ends(didEndContact is called). So when im like colliding with that B, collision instantly ends, then starts again, then ends, then starts again.... What i want is that if A collided with B, A will lay on this B. I noticed i could achieve that by setting A.dynamic = NO, but i need to apply velocity to A, and if its not dynamic, velocity wont work.
This is the code:
typedef NS_OPTIONS(uint32_t, CollisionCategory)
{
CollisionCategoryPlayer = 1 << 0,
CollisionCategoryDiggable = 1 << 1,
};
-(void)didMoveToView:(SKView *)view
{
self.playerNode = [SKSpriteNode spriteNodeWithImageNamed:#"player"];
self.playerNode.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:self.playerNode.size];
self.playerNode.physicsBody.categoryBitMask = CollisionCategoryPlayer;
self.playerNode.physicsBody.collisionBitMask = CollisionCategoryDiggable;
self.playerNode.physicsBody.contactTestBitMask = CollisionCategoryDiggable;
self.playerNode.position = CGPointMake(160, 520);
self.playerNode.name = #"player";
self.playerNode.physicsBody.allowsRotation = NO;
self.playerNode.physicsBody.friction = 0;
[self addChild:self.playerNode];
SKSpriteNode* spriteNode = [SKSpriteNode spriteNodeWithTexture:textToUse];
spriteNode.name = keyFromCoordinate(coord);
spriteNode.position = CGPointMake(160, 400);
spriteNode.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:spriteNode.size];
spriteNode.physicsBody.dynamic = NO;
spriteNode.physicsBody.categoryBitMask = CollisionCategoryDiggable;
spriteNode.physicsBody.collisionBitMask = CollisionCategoryPlayer;
spriteNode.physicsBody.contactTestBitMask = CollisionCategoryPlayer;
spriteNode.physicsBody.resting = YES;
[self addChild:spriteNode];
}
-(void)update:(NSTimeInterval)currentTime
{
self.playerNode.physicsBody.velocity = CGVectorMake(0, -200);
}
And again the problem is that didBeginContact is called, then didEndContact, then didBegin and so on, what i want is - did begin is only called once.

Answer 1

Setting the restitution = 0 for both physicsBodies helped