Reproduction steps:
1. Create a new project
2. Go to Project Settings -> Player -> Android tab -> Splash Image
3. Disable "Show Splash Screen"
4. Add a custom Static Splash Image
5. Build and Run on Android

Expected result: Custom Image of Splash Screen remains in the same position while loading
Actual result: Custom Image of Splash Screen moves down with Navigation bar while loading

Reproducible with: 2018.4.32f1, 2019.4.19f1, 2020.2.5f1, 2021.1.0b5, 2020.2.0a5

Reproducible with:
VLNQA00030, Lge LG G2, Android: 4.4.2, CPU: Snapdragon 800 MSM8974, GPU: Adreno (TM) 330
VLNQA00122, Samsung Galaxy S9 (SM-G960F), Android 10, CPU: NOT FOUND, GPU: Mali-G72
VLNQA00042, Lge LG G3 (LG-D855), Android 5.0, CPU: Snapdragon 801 MSM8974AC, GPU: Adreno (TM) 330
VLNQA00285, Samsung Galaxy J4 Core (SM-J410F), Android 8.1.0, CPU: Snapdragon 425 MSM8917, GPU: Adreno (TM) 308

Not reproducible with:
VLNQA00321, Xiaomi MI 9 (MI 9), Android 10, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640 (possibly happens too fast to notice)
VLNQA00277, Asus ROG Phone, Android: 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00006, Samsung Galaxy S7, Android: 8.0.0, CPU: Exynos 8 Octa 8890, GPU: Mali-T880