It is probably a bug, but again Spotify has drawn a line to 'define' Linux Support.
From [0]
'Spotify for Linux is a labor of love from our engineers that wanted to listen to Spotify on their Linux development machines. They work on it in their spare time and it is currently not a platform that we actively support.'
Looking at the multiple issues in the help section, it seems that in addition to this issue, it seems that Spotify doesn't care that much about Linux.
[0] https://www.spotify.com/uk/download/linux
