How do I show Apple Maps turn-by-turn navigation for public transport on my lock screen and Apple Watch?

I use the iOS Apple Maps app frequently for public transport directions. In the past, if I was actively navigating using public transport, Maps would display turn-by-turn directions on the lock screen and on my Apple Watch. Since upgrading to iOS 13 this doesn't happen, although I still get turn-by-turn on the lock screen and watch for driving and walking directions. How do I get turn-by-turn back for public transport?