IOS podcast playlist groups by show even though I don't have that selected

I have a selection of podcasts I've enabled in one playlist. I want to play them from oldest to newest regardless of the particular podcast, so select that order in the playlist, and unselect 'Group by Show'. When I look at the playlist, it shows all the podcasts in the expected order. When I select play on the first podcast from within the playlist, I expect it to move to the next one in playlist order, but most of the time it moves to the next one in the particular podcast instead. This happens more often when there are a lot of podcasts pending in the playlist, but I haven't found any trick that makes it behaves correctly consistently.