SKAction truncation completion block is not executed in iOS 11 devices

Question

Here is the piece of code I m using.

__weak typeof(self) weakSelf = self;
[self.bringContinentInNode runAction:bringInAction completion:^{
    [weakSelf.baseNode removeFromParent];
    weakSelf.baseNode = nil;
    weakSelf.baseNode = weakSelf.bringContinentInNode;

    weakSelf.continentName = weakSelf.transitionContinentName;
    [weakSelf fetchData:YES];
    [weakSelf createRoadMapView:NO showBuyView:NO];

    weakSelf.userInteractionEnabled = YES;
}];

The code inside completion block is never executed in iOS 11 but works on iOS 10 and below. Can somebody tell me why this happens?