Reproduction steps:
1. Open the attached “SluggishAreaLightRealtimeGI 2.zip“ project
2. Open “OutdoorsScene” scene
3. Enter Play mode
4. Press “J” key to turn Area lights purple
5. Observe the Game window
6. Press “K” key to turn Area lights grey
7. Observe the Game window
8. Press “L” key to change lights to Spot lights
9. Do 4-7 steps with Spot lights

Expected result: Area lights change intensity smoothly
Actual result: Area lights change intensity by flickering

Reproducible with: 2021.3.19f1, 2022.2.8f1, 2023.1.0b6, 2023.2.0a4
Could not test with: 2020.3.45f1 (Due to errors in Console window)

Reproduced on: Windows 11
Not reproduced on: macOS Monterey 12.6 (Intel)

Note: Also reproducible in Build