How to reproduce:
1. Open the attached “IN-96698_MathActionShooter“ project
2. Open the “SampleScene“
3. Build and run the project, make sure it’s a WebGL build
4. Look / walk around the environment using the WASD keyboard buttons
5. Observe the results

Expected result: A shadow does not appear underneath the Camera
Actual result: A circular shadow appears and disappears underneath the Camera

Reproducible with: 6000.0.35f1 (9a3bc604008a), 6000.0.43f1, 6000.1.0b11, 6000.2.0a7
Not reproducible with: 2022.3.60f1, 6000.0.34f1

Reproducible on: Windows 10, Windows 11 (by user)
Not reproducible on: MacOS 15.3 (M4)

Notes:
- The issue only reproduces on a WebGL build
- Reproduced on Google Chrome, Firefox, Microsoft Edge
- Doesn’t reproduce on Safari
- Removing the "Cube" GameObject or disabling its "Cast Shadows" option (found in the Inspector window, under Mesh Renderer component) from the Hierarchy window causes the issue to stop reproducing
- Removing the Terrain from the Hierarchy window and changing it to a Plane GameObject stops the issue from reproducing