Reproduction steps:
1. Open project in "Project.zip" and build it for iOS (any scene)
2. Open Xcode project generated
3. In project navigator Select DesignHomeSplash.storyboard
4. Right to project navigator Select DesignHomeSplash -> View -> splash.png
5. Right of Xcode open Image View (Icon with sliders)
6. Select splash.png as the image
7. Open Data/Raw folder in finder (right-click, then click show in finder using Xcode project navigator)
8. Drag the contents of the folder to the Root in Xcode project (if skipping this step the screen splash screen will be white)
9. Deploy the project to an iOS device
10. Inspect the launch screen

Expected result: The splash screen is visible immediately
Actual result: There is a black screen before the splash screen becomes visible

Reproducible with: 2018.4.35f1, 2019.4.27f1, 2020.3.9f1, 2021.1.7f1, 2021.2.0a17

Reproducible with:
iPhone 12 (iOS 14.1)
Not Reproducible wth:
iPad Pro 12.9 1st gen (iOS 13.4.1)

Notes:
1. I attached a video on how the setup is done in Xcode "2021-05-21 12-15-43.mp4"
2. Issue can be seen in video "VID_20210316_135029.mp4"
3. The issue does not occur when adding the image to Xcode directly (when image is not added via streaming assets folder)