Steps to reproduce:

1. Download the attached project and open the scene.

2. Open Scene view and look at the light probes, they are very inconsistent, some are completely black.

Notes:

- This is not exclusive to the GPU progressive lightmapper, it happens with the CPU one too.

- The workaround is to massage the light probes (slightly move them) and keep doing it until they happen to get better values. This issue, combined with the fact that I cannot re-bake just the light probes, makes it very hard to have nicely placed and lit lightprobes in my scenes.

- This is not specific to 2019.2, it happens in all versions.