This may be a label problem but Spotify has an annoying tendency to mix up stereo and mono versions of some 60s albums. Some albums by, say, Kinks and Hollies have been released on CD in versions containing both complete stereo and mono versions, and when asking to play the stereo tracks, Spotify will often just play the mono version instead. When a CD contains two different mixes of the same song, we should expect to be able to get both mixes on Spotify, not the same mix twice. 

This is a problem with several The Hollies issues (almost all mono/stereo albums from before 1968-ish) and also with the Deluxe version of "Something Else by The Kinks".