Steps to reproduce:

1. Open an existing Unity project
2. Navigate to Lighting Settings window
3. Bake the lighting using any Lightmap Parameters preset
4. Once the bake has finished, select another Lightmap Parameters preset
5. Click on generate lighting button again
6. Notice that the lightmap is not rebaked

Notes:

- Affects both the CPU and the GPU lightmappers
- One way to get around this issue is to clear the baked data and rebake
- Please see the attached video for the repro steps