https://www.youtube.com/watch?v=5rPUmYzzbgY
I'm migrating my project to Unity 2020.3.26 from 2019.4. After generating lights, in 2020.3, textures turn black & flicker. I don't know what's going on. This doesn't happen with 2019.4.
I'm using a texture atlas to minimize draw calls...I am getting warnings about overlapping UVs. Again, I ignored those warnings in previous versions because I didn't have these problems.