Here is a video to demonstrate the bug.
(skip to 0:24 if you do not want to see low, high, and ultra settings)
This bug will happen on medium shadow quality.
Low, High, and Ultra shadow qualities do not have this issue.
If you are in full third-person view,
you will not be able to see the flashlight.
If you are in first-person view
or
if you back up into an object so that your camera moves forward,