I too have version 9 on a S. Specifically va9.0(2018.48.12.1.xxxx). Spotify is a disaster on it. Even more so than on version 8. Many lockups of the screen/MFD and countless "Loading..." infinite loops. On the rare occasion it gives you an error message then the message will contain zero useful information. Mostly it just says "try again".
It is unclear where the fault(s) lay. Maybe Tesla C code, maybe Spotify, maybe non-rigorous interface between the two. Definitely non-rigorous handling of varying 3G signal strength. Two bars is not good enough and often 3 bars. Sometimes in a city you have 4 bars but still Spotify is stuffed whilst TuneIn works.
Bugs like this can distract a driver and thus compromise safety. You have to avoid fiddling with it whilst driving. All due to woeful software quality validation, and highly suggestive of Tesla's source code being "spaghetti" C code.
Many bugs are solid-ON. In other words the exact same sequence of user selections will result in the same problem every time. Others are more horoscope-like.
Obviously behaviour (perfect/bugs) "should" be identical between vehicles running the exact same release variant.
I hope the US drivers will "be careful what you wish for" apropos Spotify replacing Slacker.
And the rest of version 9 is a disaster too. Slow/missing manual pages, failure to bring up reversing camera when going to R (under various scenarios), and the "nav screen whether you want it or not". Erratic Bluetooth connectivity.
R6.