Black screen in a build for IOS

i have a big problem with unity. I created a game and when I create the image for IOS, I open Xcode with the project, and I text it with my iPhone 8, the screen turns totally black. In addition, from this morning he also reproduced sounds, which are not found in the first scene. Not even the UI objects can be seen. However I'm sure something happens, because in the Xcode debug tab, there are various values ​​that change. Also, seeing the GPU values, I noticed that it reached a peak of 109%, although I don't know how it can be possible, but the value while looking at it is 0%. Finally I would like to emphasize that when I open the game, the image with the Unity logo is reproduced first and then the black screen arrives. Finally I would like to say that I also tried with another version of united: the 2019.2.1f1 version, and in that case the interface was visible, but it was very enlarged, even if I tried to change the settings of the canvas scaler. How can I do? In all other platforms this does not happen. I have read all the forum pages that included this problem, but no advice has worked. The version I am using now for Unity is 2020.1.0a18. iPhone 8 with IOS 13.3, and the latest Xcode update. PS. I have also tried with an iPhone 6 with IOS 12.4.3, but it has the same result.