CarPlay stopped giving turn-by-turn voice directions

A month ago I would get voice turn-by-turn directions while connected to CarPlay. It has recently stopped. I know it is trying because if I'm listening to music, the music would go silent while a drive instruction is given. But the instructions are silent. Then the music would return to desired volume. If I tell Seri to stop music, she does as instructed, but still no voice on drive instructions. What's happening?

[Re-Titled by Moderator]