1) Download attached project and open in Unity
2) Build and run project on a device
Observe the black screen (the app is not freeze, it just compiles the shaders very long)

Reproduced with:
2019.1.0a2 - 6 minutes took to launch the game scene (Nexus 7)
2018.3.0b4 - 7 minutes took to launch the game scene (Nexus 7)

Devices under testing:
Reproduced with:
VLNQA66653 Google Nexus 7, OS:5.1.1, CPU:armeabi-v7a, GPU:NVIDIA Tegra 3
VLNAQ00055 Samsung SC 06D (Galaxy S3), OS:4.1.2, CPU:armeabi-v7a, GPU:Adreno (TM) 225

Not reproduced with:
VLNQA00126 Samsung SM G800F (Galaxy S5 Mini), OS:6.0.1, CPU:armeabi-v7a, GPU:Mali-400 MP
VLNQA00202 Samsung Galaxy Note9, OS:8.1.0, CPU:arm64-v8a, GPU:Adreno (TM) 630
VLNQA00178 Xiaomi Redmi Note 4, OS:6.0, CPU:arm64-v8a, GPU:Mali-T880