Pixels seem to stop updating in the path tracer when a camera stops moving in sequence. Old color values from objects that have moved seem to still affect pixels they should not.
When the camera stops moving there will be severe ghosting of the sphere for the remainder of the shot. ([See attached video|[Link Removed]])
The object should not leave a ghosting trail, as seen before the camera stops moving.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-78307 in the post.