A separate thread for this got zero replies, so I'm going to move forward with this being a bug needing reported:
I have added a smartlist to the Car Radio set that is supposed to play Podcasts in order from most recent. On it's own, the smartlist functions as expected but, when clicking on the Car Radio preset containing the smartlist, the tracks are always played in a random order.
The smartlist couldn't be much simpler:
[Media Sub Type]="Podcast" ~sort=[Date]-d
I used to always get the latest news podcast first, so I don't think I was having this problem before upgrading to MC19, but can't swear it coincided with the version upgrade.