How to reproduce:
1. Open the attached "IL2CPP_Repro" project
2. Build and run the project on an Android device
3. Get the logs using 'adb logcat'
4. Find the "Socket select took ..." line

Expected results: Socket select took 10 or 11
Actual results: Socket select took 0

Reproducible with: 2017.4.36f1, 2018.4.15f1, 2019.2.17f1, 2019.3.0f4, 2020.1.0a18

Devices used for testing:

Samsung Galaxy Note 2, Android 4.4.2, CPU: Samsung Exynos 4 Quad (4412) GPU: Mali 400 MP4
Xiaomi Mi 5s (MI 5s), Android 6.0.1, CPU: Snapdragon 820 MSM8996, GPU: Adreno (TM) 530
Samsung Galaxy Note8, Android 8.0.0, CPU: Snapdragon 835 (MSM8998), GPU: Adreno (TM) 540
Xiaomi Mi A1, Android 9.0.0, CPU: Snapdragon 625 (MSM8953), GPU: Adreno (TM) 506
Google Pixel 2 XL, Android 10, CPU: Snapdragon 835 (MSM8998), GPU: Adreno (TM) 540

Additional note: The Select() method works correctly with Mono