Steps to reproduce:

1. Create a new project using either LWRP or HDRP template
2. Navigate to the lighting window, and make sure that Lighting Resolution is set to 8 or lower
3. Bake the scene lighting
4. Switch to the UV Overlap scene view mode
5. Notice that nothing shows up

Notes:

- Affects both LWRP and HDRP; Built-in RP is not affected
- Lightmap preview window still shows UV overlaps
- Tested in: 2018.3.5f1, 2019.1.0b3, 2019.2.0a5
- Tested using the following package versions: 5.2.3-preview, 5.3.1-preview