How to reproduce:
1. Open SampleScene from the “Lightmap ExposureTest.zip” project
2. In the Scene view control bar set Draw Mode as “Baked Lightmap”
3. Set Lightmap Exposure to any value other than 0
4. Enter and exit the Play mode

Expected result: After returning from Play mode the Lightmap Exposure stays the same as before entering the Play mode

Actual result: Returning from play mode Lightmap Exposure resets but the slider still shows the old value

Reproducible with: 2020.2.0a19, 2020.3.18f1, 2021.1.20f1, 2021.2.0b9, 2022.1.0a7
Not reproducible with: 2019.4.30f1, 2020.2.0a18

Notes:
- After returning from Play mode 3rd time, Lightmap Exposure no longer resets.