Sun visible trough blocks and glowing blocks seems to be related to to LabSSS, and there's also godrays going trough Distant Horizons LOD models.

the godrays go through the mountain because there is no shadowmap to block it. increase the shadowmap distance.
the sunlight thing, this is screen-space shadow's subsurface scattering dying. you can either turn off subsurface scattering or turn off screenspace contact shadows in direct light -> shadows