Alexa commands don't work the same!??

[photecs]

So, i've had Alexa (2nd gen echo DOT) for a few months connected to my Spotify - love it.  I ask for light jazz during dinner, done.  I ask for 90's rock, done.

I bought my Parents a 2nd gen Echo and 1 year of Premium Spotify for Xmas... when we ask for 50's music it says "I can't find 50's music".  If you ask for a specific playlist name "All about the 50's", it plays.  If you ask for light jazz, same thing!
If you don't ask for a specific name of artist or playlist, it can't find it... but with mine, I just ask for a time period or genre, and it works...

Settings are identical... any ideas?!