podcasts not appearing in playlist

I have a podcast playlist that I manage manually in iTunes. When I sync it a few of the podcasts don't appear on the equivalent playlist on my phone. The podcasts in question are on the phone as they're visible in 'Unplayed' and 'My podcasts', just not in the playlist. Have subscribed to the podcasts for ages and have had the playlist for a long time too. I've experienced the problem for a few months. Deleting and recreating the playlist hasn't helped.

Any advice gratefully received.

iTunes 12.3.2.35, iOS 9.2