Reproduction steps:
1. Open the attached "FPSDropWebGL.zip" project
2. Build and run the project
3. Once the WebGL build runs in the browser, press the “Press to play“ button. The video will start playing
4. Observe the FPS counter in the top left of the Player window

Expected result: FPS does not drop down when the video starts
Actual result: FPS drops down significantly

Reproduced with: 2021.2.0a12, 2021.3.23f1, 2022.2.16f1, 2023.1.0b13, 2023.2.0a11
Not reproduced with: 2020.3.47f1, 2021.2.0a7
Could not test with: 2021.2.0a8-2021.2.0a11 (could not resolve console errors after the WebGL build attempt)

Reproduced on: Windows 10