Looks like I found the reason.
If use 1 name for all phone numbers everything will be fine, 1 million numbers will be added in about 100 seconds. If use about 100 names - about 140 seconds. If use unique names for all numbers - from 270 to 1800 seconds.
Hope Apple fixes it.
I've changed .barTintColor to UINavigationBarAppearance backgroundColor, set to standardAppearance and scrollEdgeAppearance and it works. But if present new ViewController modally with modalPresentationStyle == .fullscreen and dismiss, navigationBar's background color on the first one changed to default.
Looks like I found the reason.
If use 1 name for all phone numbers everything will be fine, 1 million numbers will be added in about 100 seconds. If use about 100 names - about 140 seconds. If use unique names for all numbers - from 270 to 1800 seconds.
Hope Apple fixes it.
I've changed .barTintColor to UINavigationBarAppearance backgroundColor, set to standardAppearance and scrollEdgeAppearance and it works. But if present new ViewController modally with modalPresentationStyle == .fullscreen and dismiss, navigationBar's background color on the first one changed to default.