Hi, I'm new to this forum and CCTV, so sorry if this is very basic. 4 PoE camera and 2TB NVR set up, no real problems. Internet connection to NVR easy. Tablet access to NVR using IP address shows setting and management (inc. still pictures from cameras), but no Preview or Playback. NVR set to record Motion and I can see dates and times of recordings, but no video. Do I really have to use an App on my Tab to see video, please?