Vary thx again with this and another one my question) I've already seen this and as I understand all solutions beed deprecated.

Very thx I think I can use the 1% / minute system for first 2% and than I will have enough info for calculate it.

Launch storyboard. I also do not understand why so.

Yeah. I sure. I use real devices for tests. I have already find the answer. Thx for your attention. The problem was with the launch screen in the Project setting. When opening in Xcode 12 for some unknown reason Launch screen field was empty. And scene bound has been set up as 320 x 480. As soon I set the correct launch screen - the problem was solved.