This is the transition problem during the merger. Amateur video software will not have this problem if it does projects such as voice and shadow and splitit.

If you want to eliminate it, you can change a combiner, such as splitit, or manually add an audio and video transition.

In fact, is the landlord a little obsessive-compulsive At this moment, the transition time of the black screen does not exceed half a second, which has no effect at all ~

Have questions to ask.