I use Libreelec with the default skin under a Raspberry4.
Since I prefer to decide myself the genre of a movie, I keep them separated on my disk under different directories (Action,Cartoon etc) - and I added all of them as a source to Libreelec.
This way, I can browse everything under "Movies", or I can go under Video>Files, find my directory, and e.g. browse all the Cartoons.
Under the previous version (time ago, it was just "Kodi" then) I could set that the view was as thumbnails.
Unfortunately with this version under Video>Files the only view allowed seem to be the one showing each movie as a folder (I keep every movie in its folder).
I know it can seem a small problem, but for me it makes for a lot worse experience... is it possible to re-activate the thumbnails view?