Scrobbling issue (Last.fm)

[SophiaPangloss]

Hi, can anyone help? I use Spotify on PC & Android, and both scrobble tracks easily to Last.fm, but if I try to play a track on Spotify from Last.fm it sees Spotify, but then doesn't recognise it and asks me to set up an account. I've done all the usual logging out, re-installing etc, no luck... any ideas?