How to reproduce:
1. Create a new Unity Project
2. Select WebGL platform
3. Build the project
4. Navigate to the build folder through the terminal e.g., cd /Users/username/unity_project/Build
5. Start a webserver with: http-server --port 8080
6. The webserver should show the address with the local IP of your Mac on the console, e.g., http://192.168.0.191:8080
7. Open this address on any mobile device that is connected to the same network
8. Rotate mobile device to landscape

Expected result: The view is rotated
Actual result: Half of the screen is not rendered

Reproducible: 2022.2.0a1

Reproducible on:
Samsung Galaxy S21 Ultra (SM-G998B), Android 11, CPU: Exynos 2100, GPU: Mali-G78
VLNQA00287, Motorola moto g(7) power (moto g(7) power), Android 9, CPU: Snapdragon 625 MSM8953, GPU: Adreno (TM) 506
VLNQA00336, Huawei Y6p, CPU: MediaTek MT6762R, GPU: PowerVR Rogue GE8320, Android: 10
VLNQA00103, Samsung Galaxy Note8 (SM-N950F), Android 7.1.1, CPU: Exynos 9 Octa 8895, GPU: Mali-G71
iPhone 13, A15, 15.0

Tested and reproduced on these Browsers:
Google Chrome (Samsung S21, Motorola g(7))
Safari (iPhone 13)
Huawei Browser (Huawei Y6p) - issue reproducible with portrait orientation as well
Samsung Internet Browser (Samsung Galaxy Note8)