[djtn]

As perfectly decribed and documented (very early by myself ;-) TWO YEARS AGO) and in January 2019 by Pixelate 61 above this reply and again mentioned by memphis above this problem still exists.
The good news is that is was fixed in Kodi 18 but only in the windows version.
The problem still exists unchanged on the Libreelec version even in the latest with Kodi 18.

With kind regards
Martin Klein

It's a shame that nobody from the dev team has a focus on fixing this severe issue for more than 3 years now. This is why I'm still on 15.2 (on Nvidia shield), which is the latest release with a working slideshow for more than 12000 pics/vids. Even the mentioned windows release of 18.1 has severe problems with slideshow stability, not to mention that it struggles with large amounts of multimedia data.