I've encountered this sometimes after the console display has been rebooted, software updated, or the car resumes from the deep sleep mode. But it hasn't happened much recently.
I've created a long favorites list for my USB music, and that's what I usually play. Almost all of the time, when I select USB, it resumes playing the last song played in the favorites playlist. But when one of the above event has occurred, I might see that the USB is not listed playing a song - so I have to go back and manually select the song to play - and then after that, it has worked pretty well.
A bigger frustration is in playing audiobooks through my phone over Bluetooth. Every time I leave and return to the car, the Bluetooth connection to my phone has to be manually selected. And I usually have to go my phone's display to resume playback of the audiobook.