Comment by mkobit

They wrote an interesting blog some time back about how "random shuffle" isn't necessarily what people want, and how their algorithm works (https://engineering.atspotify.com/2014/02/how-to-shuffle-son... ). That was a decade ago, so maybe their approach has changed or that it does not perform well under certain conditions (like the one you mention). It works well for me on most playlists on the order of 10s.