I have a light source in the first room. All my walls are BSP and in the second room (no lights) you can see the reflection of the lights in the first room. I have placed a reflection capture and still no luck. Im also a beginner in UE4.
When using reflections will want to use smaller radius’ and/or box reflecftions for box like rooms. The Reflection Capture does not get occluded from geometry, such as walls. So if you have a large radius on your reflection sphere it will surely be visible outside of the area you would like.
These two pieces of documentation can help you get setup and using reflection captures more accurately.