Using Lightroom Classic CC v7.2. Using Slideshow Export to create a video with sound from a collection. The collection has 159 photos plus 7 short video clips interspersed among the photos. The slideshow uses 7 music files. It is set to make the slideshow "Fit to Music" so it is 18:03 minutes long. When exporting in Standard Quality the resulting file does not play properly. At a point perhaps halfway through the file the image is no longer displayed, although the music continues! The playback problem happens both when the file is on a USB drive plugged into a DVD player and when it is played back on a computer.
Bypass: I was ab/e to bypass the problem by Exporting the Slideshow in High Quality mode. That file is about 1gb bigger and does display correctly.