The screen blinks when transitioning from custom to Unity splash screen

Steps to reproduce:
1. Open the “IN-121544” project
2. Build the Xcode project
3. Open the built project on Xcode and deploy it on any simulator
4. Observe the device screen at the start

Expected result: A smooth fade between the custom set splash screen and the default Unity splash
Actual result: The display blinks when transitioning to the splash screen

Reproducible with: 6000.0.56f1, 6000.0.60f1, 6000.1.17f1, 6000.2.7f1, 6000.3.0b4, 6000.4.0a2
Not reproducible with: 6000.0.55f1

Testing environment: macOS 26.0 (M4 Pro), 26.0.1 (M4 Max)
Not reproducible on: No other environment tested

Notes:

• Also reproducible with physical devices
• Using UI/Default