I’m sorry, but I still don’t know what it is you are trying to do when you get the error code; from a computer, from the Podcast app, or whatever.
All said, I’m not an expert, so I probably won’t be able to help either, but I need a detailed explanation of the steps you are taking on what device and using what app(s). There a several ways you could be attempting to download podcasts, and until I know what method you are using, I can’t even guess what might be going wrong.
I don’t know, or particularly care about what most error messages mean. Much of the time the explanatory text (if you can find it) is obscure, meaningless to anyone who didn’t write it. I care about what you are doing, so that I can guess at the things the can go wrong. Often the fix has nothing to do with the error message anyway. It usually just ‘do this instead’.
Most of the time, I don’t even try to download podcasts outside the app I’m going to use to listen to them. Even when switching apps, I usually configure the new app to subscribe to the podcast or download the episodes from the source again. The only time I’d try to copy a podcast from one app/device to another is if it was no longer available online.