I wasn't sure where to go looking for this issue. I found many hits that relate to my problem in different ways on different devices, but none of those fixes really worked for me. 

Device: OnePlus One running Cynageon Mod 11s (4.4.4) 

I don't know if this is a Spotify thing or a ROM thing with my OnePlus One. I remember not having this issue about a month ago. 

What I mean by disappearing is that the app will still be playing in the background and the device knows that music is playing because my lock screen shows a visual EQ effect when its playing something, but the play, pause, forward, and back controls disappear and so does the album art on the lock screen. I've also noticed that whenever the playback controls do disappear from my lock screen, the in-line controls on my earphones stops working also. 

Here's a list of instances that I noticed will cause the play back controls to disappear from the lock screen.

- Whenever the app wasn't the last thing running in the forground before locking the screen.

- Whenever app was left in a sub menu of some discription and not what is currently playing.

- Whenever screen stays locked while the app trasitions from one song to the next

- Whenever I connect or disconnect my earphones with mic while the app is running. 

- Whenever I transition from mobile to desktop and vise versa using Spotify Connect. 

- **Whenever I'm roaming around college campus and being constantly disconnected and reconnected to wifi.

I believe the instance I marked with ** is the biggest offender. I don't know how because I play off of playlists I have downloaded. 

Play Back Controls Working / NOT Working