Very similar problem for me. A podcast has several different episodes per day broken down by hour. It will totally mix up the files and names and descriptions, seemingly grabbing them from random days surrounding what it should be. Sometimes two simlarly named files will play the same audio. It's totally messed up. I can't figure out any pattern for this either.
Although I'm sure it happens for podcast episodes with titles that are not similar as well.
They fixed nothing! I can't stand this disgrace anymore. Don't tell me it is very difficult to make it working. It worked in iPod app. Apple doesn't even have to develop anything new - just reuse well working solution - and they screwed.
Please, somebody, advice normal podcast manager, i.e. just any other than this Podcasts app.