Apple Podcasts app will sometimes delete all my downloaded episodes

I'm old school (and just plain old), so the way I manage podcasts is by downloading them in iTunes (on Windows) and then syncing it to my iPhone. Works really well. I like knowing exactly what I have available to listen to. If I finish an episode, I delete it in iTunes, and then it'll be removed from my phone next time I sync it.

But I noticed recently that on seemingly random occasions, I'll go the Library -> Downloaded section of the app and it'll be completely empty! If I connect it to iTunes and sync, it'll copy all my episodes over, as if they were never copied over before.

I think one time this might have corresponded with an iOS update, but two other times, it just happened over night when no update that I know of was installed.

Anyone experience this or know if this is a known bug?