SpotLight Problem

Hi … I want to turn on the dark environment into a sphere with the Spotlight. Within this environment there is a transparent object. When the spot light radiates to the object, the color of the object changes and becomes very dark. This problem does not occur in other types of lights (sky or point light). I’m new in modelling and unreal and I could not fix the problem by changing the light spot setting. I tried to make better the environment color by using the Post Process Volume, but the problem did not resolve. Can anyone guide me in this case? Thank you.