Weird uitableview behaviour in iOS11. Cells scroll up with navigation push animation

This is due to UIScrollView's (UITableView is a subclass of UIScrollview) new contentInsetAdjustmentBehavior property, which is set to .automatic by default.

You can override this behavior with the following snippet in the viewDidLoad of any affected controllers:

    tableView.contentInsetAdjustmentBehavior = .never

https://developer.apple.com/documentation/uikit/uiscrollview/2902261-contentinsetadjustmentbehavior

In addition to maggy's answer

OBJECTIVE-C

if (@available(iOS 11.0, *)) {
    scrollViewForView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
}

This issue was caused by a bug in iOS 11 where the safeAreaInsets of the view controller's view were set incorrectly during the navigation transition, which should be fixed in iOS 11.2. Setting the contentInsetAdjustmentBehavior to .never isn't a great workaround because it will likely have other undesirable side effects. If you do use a workaround you should make sure to remove it for iOS versions >= 11.2

-mentioned by smileyborg (Software Engineer at Apple)