Reproduction steps:
1. Open the attached Unity project "WebRequestIssue.zip"
2. In the Project window navigate to Assets folder > Scenes folder and open "SampleScene.unity" Scene
3. Go to File > Build Settings
4. Switch to the Android platform and Build and Run the project on a device
5. Open Android Logcat and observe the error in the logs

Expected result: No errors are thrown in the logs
Actual result: Errors is thrown in the logs: "NullReferenceException: Object reference not set to an instance of an object"

Reproducible with: 2020.3.31f1, 2021.2.14f1, 2022.1.0b11, 2022.2.0a7
Could not test with: 2019.4.36f1 (an error is thrown in the logs: "WebException: Error: NameResolutionFailure")

Reproduces with these devices:
VLNQA00277 - Asus ROG Phone (ASUS_Z01QD), OS: 9.0.0, CPU: Snapdragon 845 SDM845, GPU: Adreno 630
VLNQA00147 - Razer Phone (Cheryl), OS: 8.1.0, CPU: Snapdragon 835 MSM8998, GPU: Adreno 540
VLNQA00404 - Galaxy Z Flip3 5G (SM-F711B), OS: 11, CPU: Snapdragon 888, GPU: Adreno 660
VLNQA00219 - Samsung Galaxy Note9 USA (SM-N960U), OS: 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno 630
VLNQA00121 - Samsung Galaxy S9 (SM-G960F), OS: 9.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00263 - Google Pixel 3 (Pixel 3), OS: 12.0.0, CPU: Snapdragon 845, GPU: Adreno 630
VLNQA00006 - Samsung Galaxy S7 (SM-G930F), OS: 8.0.0, CPU: Exynos 8 Octa (8890), GPU: Mali-T880
VLNQA00022 - Xiaomi Redmi Note 3 (Redmi Note 3), OS: 6.0.1, CPU: Snapdragon 650 MSM8956, GPU: Adreno 510

Not reproducible with these devices:
VLNQA00358 - iPhone 12, 14.1 iOS
VLNQA00310 - iPad Pro 12.9", 13.4.1 iOS
VLNQA00392 - iPad (9th generation), 15.0 iOS

Notes:
- Issue is not reproducible when using IL2CPP Scripting Backend
- Issue is not reproducible in the Editor