Are you talking about ones in our personal collections? Or ones that replaced others in a publisher's product line?
not that this is going to solve you problem, but I'm wondering if you can play the podcast from it's browser page.if so, then your machine is capable of parsing the file, and it's a different problem
But not to be a podcast snob, for lots of good or not-so-good reasons, I use my podcast app for all of my podcast listening.
I posted a screenshot on the ACD Discord channel.