Solution:
First make sure if the video is discontinuous, or if the playback is not smooth. If the video is discontinuous, you may have enabled "Only record video when motion is detected", therefore the camera only records when movement is detected. If the problem is the playback not being smooth, it may be caused by insufficient upload bandwidth or other network related issues. Make sure the network that the camera is connected to is not overloaded with devices, or if other devices are taking up a lot of bandwidth.
Does it help?