Phone - Android - Samsung Other (Specify in description)
I'm loading in world for 188.8.131.52 beta but still generated 9 chunks and light is broken.
To users searching for this bug
There are currently two unrelated bugs having similar symptoms of dark shadows:
This bug causes unusually dark but still gradual shadows. It can be worked around by momentarily placing a torch or other light source in the shadowed area, or by any action that would cause a lighting update such as breaking blocks above the shadow to expose it to the sky light.
MCPE-39368 describes a bug that causes fully black shadows with sharp edges, even right next to a light source. Placing a torch does not correct this problem.