Regardless, Cubase 10 hangs every time I quit the application even when no song / plugins have been loaded. I have to then force quit the application.
I experience this also even with totally empty Projects, although not everytime i quit C10.
The majority of the times i quit C10, it quits without Hang.
But sometimes when quitting: the rotating Beachball appears and C10 hangs.
Been experiencing this “hang on quit” issue may times with previous versions of Cubase also, seems it is still an issue 
Next time it happens, i will have a look a the OSX Console utility application during the hang, to see if i notice some message related to the hang.
My other DAW’s like Reaper, Logic Pro and Ableton Live don’t have a “hang on quit” issue at all.
OSX 10.14.1
Macbook Retina mid 2015
UA Apollo Twin (TB version)