1 Please refer to the attached project. Open the testlightchannel level.
2 The whole scene is dark initially, then check the light channel 0 on the floor actor
Result : Both the sphere and the floor are lit by the spot light
Expect : Only the floor is lit by the spot light.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-91751 in the post.