Something seemed to happen to shadows in 2.8, Here is what it looked like in 2.7, here is what it looks in 2.8 with shadows off, here is what it looks like with shadows on in 2.8; instead of adding shadows, it just makes everything darker. In-fact it looks like shadows are inversed?

Ah ok I see, the sun lighting slider behaves very differently now. Thank you.

Unfortunately, the jump from 2.7 to 2.8 requires resetting your shader settings.

Actually, even with a reset of the shader settings and using default settings, light sources during the night make weird inverse shadows when in view of the moon starting around 8pm in game time.

Side by side:

Yes, this was fixed in 2.9.